5 influence of alloying elements and aging treatment...
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5
INFLUENCE OF ALLOYING ELEMENTS AND AGING TREATMENT ON THE
PHASE TRANSFORMATION AND SHAPE MEMORY BEHAVIOR OF
Cu-Al-Ni SHAPE MEMORY ALLOYS
SAFAA NAJAH SAUD
A thesis submitted in fulfilment of the
requirements for the award of the degree of
Doctor of Philosophy (Mechanical Engineering)
Faculty of Mechanical Engineering
Universiti Teknologi Malaysia
NOVMENBER 2014
iii
To:
My beloved family
iv
ACKNOWLEDGEMENT
First of all I would like to thank Allah for this valuable time given, where I
had the chance to understand about His wonders on materials.
I am deeply grateful to my supervisor, Prof Dr. Esah Hamzah for her
guidance, patience and support. I have been extremely lucky to have a supervisor
who cared so much about my work, and who responded to my questions and queries
so promptly. I would like to thank my co-supervisor, Dr. Tuty Asma Abu Bakar for
her useful advices and encouragement. Without their valuable advice, kind
encouragement and trust, I would not have reached this point.
I would like to acknowledge the Malaysian Ministry of Higher Education
(MOHE) and Universiti Teknologi Malaysia for providing the financial support and
facilities for this research under Grant No. R.J130000.7824.4F150. I am also
grateful for the Universiti Teknologi Malaysia for their support by international
doctorate fellowship (IDF) during this research.
My thanks are also due to the staff, faculty members, and technicians of the
Faculty of Mechanical Engineering, Universiti Teknologi Malaysia, who contributed
to my research.
I am most grateful to my family, my dearest Raheleh and close friends for
their infinite support, patience and encouragements during these years.
v
ABSTRACT
Nickel-Titanium (Ni-Ti) shape memory alloys (SMAs) have been used in many
engineering and medical applications. However, their use is limited, due to their low
transformation temperatures, difficulties in processing and high cost of the raw materials. As
an alternative material to Ni-Ti alloys, copper-based alloys are successfully being used.
Among copper-based SMAs, Cu-Al-Ni alloys are used in a wide range of applications,
particularly if high temperatures are required. However, Cu-Al-Ni SMAs also have
limitations such as very low ductility and low shape recovery strain. Therefore, this research
aims to enhance the ductility and shape memory effect of Cu-Ni-Al by alloying additions
and aging heat treatment. The base metal, Cu-Al-Ni, was cast without and with different
amounts of the fourth alloying elements, namely, titanium (Ti), manganese (Mn) and cobalt
(Co). The modified and unmodified alloys were homogenized and aged at 373 K, 423 K and
523 K for 24 and 48 hours. Phase transformation and microstructural changes were
characterized using techniques such as optical microscopy, field emission scanning electron
microscopy (FESEM), energy dispersive spectrometry (EDS), differential scanning
calorimetry (DSC), x-ray diffractometry (XRD) and transmission electron microscopy
(TEM). The tensile properties and hardness were determined using a universal Instron
tensile machine and Vicker‟s hardness test machine, respectively. The shape memory test
was performed using a specially designed tensile machine equipped with a heating tape. The
results revealed that the alloying elements and aging treatment were found to control the
phase morphology, orientations and grain size along with the formation of precipitates,
thereby improving the shape memory characteristics, ductility and hardness. The volume
fraction, size and distribution of the precipitates are mainly dependent on the type and
amount of alloying element as well as the condition of aging treatment. The Cu-Al-Ni with
the addition of 0.76 wt. % Ti and age treated showed complete recovery after the shape
memory test. This may be attributed to the high volume of X-phase precipitates and grain
refinement that led to the restricted mobility of martensite variant interfaces and dislocations.
It was found that the alloy with 1.14 wt. % of Co gave the best overall improvement in terms
of the transformation temperatures, ductility and shape memory recovery. These
improvements were mainly due to the exceptionally high content of the gamma-2 (γ2) phase
in the microstructures of the modified alloy. Furthermore, the ductility of the Cu-Al-Ni
SMAs increased from 1.65 to 7.0 % when 1.14 wt. % Co was added and the alloy undergone
aging treatment where the fracture surfaces showed more ductile features and less brittle
cleavages. It was also found that Cu-Al-Ni SMAs with 1.14 wt. % Co obtained full shape
recovery after being aged at 523 K for 48 hours.
vi
ABSTRAK
Aloi ingatan bentuk (SMA) Nikel-Titanium (Ni-Ti) telah digunakan dalam banyak
aplikasi kejuruteraan dan perubatan. Walau bagaimanapun, kegunaan aloi tersebut adalah
terhad disebabkan suhu penjelmaan rendah, kesukaran dalam pemprosesan dan kos bahan
mentah yang tinggi. Sebagai bahan alternatif kepada aloi Ni-Ti, aloi berasaskan kuprum
telah berjaya digunakan. Aloi Cu-Al-Ni adalah antara SMA berasaskan kuprum digunakan
dalam pelbagai aplikasi, terutamanya jika suhu yang tinggi diperlukan. Walau bagaimanapun
Cu-Al-Ni SMA juga mempunyai kekurangan seperti kemuluran yang sangat rendah dan
terikan pemulihan yang rendah. Oleh itu, kajian ini bertujuan untuk meningkatkan
kemuluran dan kesan ingatan bentuk Cu-Ni-Al melalui tambahan unsur mengaloi dan
rawatan haba penuaan. Logam asas Cu-Al-Ni dituang tanpa dan dengan jumlah berbeza
unsur mengaloi keempat, iaitu titanium (Ti), mangan (Mn) dan cobalt (Co). Aloi diubahsuai
dan tidak diubah suai telah dihomogenkan dan dilakukan rawatan penuaan pada suhu 373 K,
423 K, dan 523 K selama 24 dan 48 jam. Penjelmaan fasa dan perubahan mikrostruktur
telah dicirikan dengan menggunakan teknik seperti kemikroskopan optik, kemikroskopan
elektron imbasan pancaran medan (FESEM), spektrometri serakan tenaga (EDS), permeteran
kalori pengimbasan kebezaan (DSC), pembelauan sinar-X (XRD) dan kemikroskopan
elektron penghantaran (TEM). Sifat tegangan dan kekerasan ditentukan masing-masing
dengan mesin Instron tegangan semesta dan mesin ujian kekerasan Vicker. Ujian ingatan
bentuk telah dilakukan dengan menggunakan mesin tegangan direka khas yang dilengkapi
dengan pita pemanasan. Keputusan kajian mendedahkan bahawa penambahan unsur
mengaloi dan rawatan penuaan didapati mengawal morfologi fasa, orientasi dan saiz bijian
bersama dengan pembentukan mendakan, oleh itu ciri ingatan bentuk, kemuluran dan
kekerasan didapati bertambah baik. Pecahan isipadu, saiz, dan taburan mendakan
terutamanya bergantung kepada jenis dan jumlah unsur mengaloi serta keadaan rawatan
penuaan. Cu-Al-Ni dengan penambahan 0.76 % berat Ti dan telah melalui rawatan penuaan
menunjukkan pemulihan lengkap selepas ujian ingatan bentuk. Ini boleh dikaitkan dengan
jumlah yang tinggi mendakan fasa-X dan penghalusan bijian yang membawa kepada mobiliti
terhad antara muka varian martensit dan kehelan. Kajian ini mendapati bahawa aloi dengan
1.14 % berat Co memberi peningkatan keseluruhan yang terbaik dari segi suhu penjelmaan,
kemuluran dan pemulihan ingatan bentuk. Peningkatan ini terutamanya disebabkan oleh
kehadiran yang sangat tinggi daripada fasa gamma-2 (γ2) dalam mikrostruktur aloi yang
diubah suai. Kemuluran Cu-Al-Ni SMA meningkat daripada 1.65% kepada 7.0 % apabila
1.14 % berat Co unsur mengaloi ditambah dan aloi menjalani rawatan penuaan di mana
permukaan patah menunjukkan lebih ciri mulur dan kurang belahan rapuh. Hasil kajian juga
menunjukkan bahawa Cu-Al-Ni SMA dengan 1.14 % berat Co mencapai pemulihan bentuk
penuh selepas melalui rawatan penuaan pada suhu 523 K selama 48 jam.
vii
TABLE OF CONTENTS
CHAPTER TITLE PAGE
DECLARATION ii
DEDICATION iii
ACKNOWLEDGEMENT iv
ABSTRACT v
ABSTRAK vi
TABLE OF CONTENTS vii
LIST OF TABLES xiii
LIST OF FIGURES xvii
LIST OF ABBREVIATIONS xxxii
LIST OF SYMBOLS xxxiii
LIST OF APPENDICES xxxv
1 INTRODUCTION 1
1.1 Background of Research 1
1.2 Problem Statement 4
1.3 Purpose of the Research 4
1.4 Objectives of the Research 5
1.5 Scopes of the Research 5
1.6 Significance of the Research 6
2 LITERATURE REVIEW 7
2.1 Introduction 7
2.2 The Development History of Shape Memory Alloys 9
viii
2.3 Martensitic Transformation in Shape Memory Alloys 10
2.4 Shape Memory Effect 19
2.5 Pseudoelasticity 20
2.6 Types of Shape Memory Alloys 21
2.6.1 Titanium-Based Shape Memory Alloys
(NiTi)
22
2.6.2 Copper-Based Shape Memory Alloys 22
2.6.3 Other Shape Memory Alloys 24
2.7 Phase Transformation and Structure of Cu-Al-Ni
Shape Memory Alloys
25
2.7.1 Phase Diagram 26
2.7.2 Martensitic Transformation 28
2.7.3 Martensitic Stabilization 29
2.8 Effects of Alloying Elements on the Cu-Al-Ni SMA 30
2.8.1 Martensitic Transformation Temperature of
Cu-Al-Ni SMA
30
2.8.2 Martensitic Structure of Cu-Al-Ni SMA 34
2.8.3 Mechanical Properties of Cu-Al-Ni SMA 39
2.9 Effects of Aging Treatment and Thermal Treatment
on the Cu-Al-Ni SMA
43
2.9.1 Martensitic Transformation Temperature of
Cu-Al-Ni SMA
43
2.9.2 Martensitic Structure of Cu-Al-Ni SMAs 47
2.9.3 Mechanical Properties of Cu-Al-Ni SMAs 52
2.9.4 Other Properties 57
2.10 Fabrication of Cu-Al-Ni Shape Memory Alloys 59
2.10.1 Melting and Casting Process 59
2.10.2 Powder Metallurgy 60
2.10.3 Melt Spinning 61
2.11 Shape Memory Alloy Applications 62
2.12 Summary
66
ix
3 RESEARCH METHODOLOGY 68
3.1 Introduction 68
3.2 Materials 70
3.3 Production of the materials by casting process 71
3.4 Homogenization Process 72
3.5 Sample Preparation for Materials Analysis and
Testing
72
3.5.1 Cutting 72
3.5.2 Grinding 73
3.5.3 Polishing 73
3.5.4 Etching 73
3.6 Materials characterization of Cu-Al-Ni SMAs 74
3.6.1 Inductively Coupled Plasma Mass
Spectrometry (ICP-MS)
74
3.6.2 X-Ray Diffractometry (XRD) 75
3.6.3 Optical and Electron Microscopy Studies 75
3.6.4 Differential Scanning Calorimetry (DSC) 76
3.7 Mechanical Test 77
3.7.1 Microhardness Test 77
3.7.2 Tensile Test 78
3.7.3 Shape Memory Effect Test (SME) 78
3.8 Aging Treatment 80
4 RESULTS AND DISCUSSION 81
4.1 Introduction 81
4.2 Evolution of the Microstructural Characteristics and
Mechanical Properties of Cu-Al-Ni SMA
82
4.2.1 Microstructural Characteristics 82
4.2.2 Transformation Temperatures 88
4.2.3 Tensile and Microhardness Tests 90
4.2.4 Shape Memory Effect Test 93
4.3 Evaluation of the Microstructural Characteristics,
Transformation Temperature, and Mechanical
x
Properties of Cu-Al-Ni-XTi SMAs 95
4.3.1 Microstructural Characteristics 95
4.3.2 Transformation Temperatures 103
4.3.3 Mechanical Properties 106
4.3.3.1 Tensile and Microhardness Tests 106
4.3.3.2 Shape Memory Effect Test 109
4.4 Evaluation of the Microstructural Characteristics,
Transformation Temperature, and Mechanical
Properties of Cu-Al-Ni-XMn SMAs
111
4.4.1 Microstructural Characteristics 111
4.4.2 Transformation Temperatures 118
4.4.3 Mechanical Properties 121
4.4.3.1 Tensile and Microhardness Tests 121
4.4.3.2 Shape Memory Effect Test 124
4.5 Evaluation of the Microstructural Characteristics,
Transformation Temperature, and Mechanical
Properties of Cu-Al-Ni-XCo SMA
126
4.5.1 Microstructural Characteristics 126
4.5.2 Transformation Temperatures 136
4.5.3 Mechanical Properties 138
4.5.3.1 Tensile and Microhardness Tests 138
4.5.3.2 Shape Memory Effect of Cu-Al-
Ni-XCo SMAs
148
4.6 Evolution of the Microstructural Characteristics and
Mechanical Properties of aged Cu-Al-Ni SMA
143
4.6.1 Microstructural Characteristics 143
4.6.2 Transformation Temperatures 149
4.6.3 Mechanical Properties 152
4.6.3.1 Tensile and Microhardness Tests 152
4.6.3.2 Shape Memory Effect Test 155
4.7 Evolution of the Microstructural Characteristics and
Mechanical Properties of aged Cu-Al-Ni-XTi SMAs
156
4.7.1 Microstructural Characteristics 156
xi
4.7.2 Transformation Temperatures 167
4.7.3 Mechanical Properties 172
4.7.3.1 Tensile and Microhardness Tests 172
4.7.3.2 Shape Memory Effect Test 180
4.8 Evolution of the Microstructural Characteristics and
Mechanical Properties of aged Cu-Al-Ni-XMn SMAs
184
4.8.1 Microstructural Characteristics 184
4.8.2 Transformation Temperatures 193
4.8.3 Mechanical Properties 199
4.8.3.1 Tensile and Microhardness Tests 199
4.8.3.2 Shape Memory Effect Test 208
4.9 Evolution of the Microstructural Characteristics and
Mechanical Properties of aged Cu-Al-Ni-XCo SMAs
210
4.9.1 Microstructural Characteristics 210
4.9.2 Transformation Temperatures 221
4.9.3 Mechanical Properties 226
4.9.3.1 Tensile and Microhardness Tests 226
4.9.3.2 Shape Memory Effect Test 235
4.10 Shape memory characteristics of SMA due to the effect
of alloying and aging
238
4.10.1 Introduction 238
4.10.2 Microstructural characteristics 238
4.10.3 Transformation temperatures 239
4.10.4 Mechanical properties and Shape Memory
Behavior
240
5 CONCLUSIONS AND RECOMMENDATIONS FOR
FUTURE WORK 243
5.1 Conclusions 243
5.2 Recommendations for future work 245
xii
REFERENCES 246
Appendices A 267
Appendices B 277
xiii
LIST OF TABLES
TABLE NO TITLE PAGE
2.1 Properties of copper-based shape memory alloys 24
3.1 Chemical composition of the cast materials used in
the research
70
4.1 The transformation temperatures of Cu-Al-Ni shape
memory alloy
89
4.2 Lattice parameters of Cu-Al-Ni SMA with Ti
additions
101
4.3 Transformation temperatures of Cu-Al-Ni SMA
with Ti additions
105
4.4 Thermodynamic parameters of Cu-Al-Ni SMA
with Ti additions
106
4.5 Fracture stress-strain, microhardness and strain
recovery ratio of Cu-Al-Ni SMA with Ti additions
107
4.6 Lattice parameters of Cu-Al-Ni SMA with the Mn
additions.
116
4.7 Transformation temperatures of Cu-Al-Ni SMA
with Mn additions
120
4.8 Thermodynamic parameters of Cu-Al-Ni SMA with
Mn additions
121
4.9 The fracture stress-strain, microhardness and strain
recovery ratio of Cu-Al-Ni SMA with Mn
additions.
122
4.10 Lattice parameters and crystallite size of Cu-Al-Ni
SMA with Co additions
132
xiv
4.11 Transformation temperature of Cu-Al-Ni SMA with
Co additions
137
4.12 Thermodynamic parameters of Cu-Al-Ni SMA with
Co additions
138
4.13 Fracture stress-strain, microhardness and strain
recovery ratio of Cu-Al-Ni SMA with Co additions
139
4.14 Lattice parameters of Cu-Al-Ni SMA under
different aging conditions
148
4.15 Transformation temperature of aged Cu-Al-Ni
SMA under different aging conditions
151
4.16 Thermodynamic parameters of Cu-Al-Ni SMA
under different aging conditions
151
4.17 The fracture stress-strain, microhardness and strain
recovery ratio of aged Cu-Al-Ni SMA at different
conditions.
153
4.18 Lattice parameters of Cu-Al-Ni-0.37 wt. % Ti SMA
under different aging conditions
166
4.19 Lattice parameters and crystallite size of Cu-Al-Ni-
0.76 wt.% Ti SMA under different aging conditions
166
4.20 Lattice parameters and crystallite size of Cu-Al-Ni-
0.99 wt.% Ti SMA under different aging conditions
166
4.21 Transformation temperatures of aged Cu-Al-Ni-
0.37 wt. % Ti SMA under different conditions.
168
4.22 Transformation temperatures of aged Cu-Al-Ni-
0.76 wt. % Ti SMA under different conditions.
169
4.23 Transformation temperatures of aged Cu-Al-Ni-
0.99 wt. % Ti SMA under different conditions.
170
4.24 Thermodynamic parameters of Cu-Al-Ni-0.37 wt.
% Ti SMA under different aging conditions
171
4.25 Thermodynamic parameters of Cu-Al-Ni-0.37 wt.
% Ti SMA under different aging conditions
171
4.26 Thermodynamic parameters of Cu-Al-Ni-0.37 wt.
% Ti SMA under different aging conditions
171
xv
4.27 The fracture stress-strain, microhardness and strain
recovery ratio of aged Cu-Al-Ni- 0.37 wt. % Ti
SMA .
174
4.28 The fracture stress-strain, microhardness and strain
recovery ratio of aged Cu-Al-Ni-0.76 wt. % Ti
SMA
174
4.29 The fracture stress-strain, microhardness and strain
recovery ratio of aged Cu -Al -Ni-0.99 wt. % Ti
SMA
175
4.30 Lattice parameters of Cu-Al-Ni-0.39 wt. % Mn
SMA under different aging conditions
192
4.31 Lattice parameters of Cu-Al-Ni-0.71 wt. % Mn
SMA under different aging conditions
193
4.32 Lattice parameters of Cu-Al-Ni-0.97 wt.% Mn
SMA under different aging conditions
193
4.33 Transformation temperatures of aged Cu-Al-Ni-
0.39 wt. % Mn SMA under different conditions
195
4.34 Transformation temperatures of aged Cu-Al-Ni-
0.71 wt. % Mn SMA under different conditions
196
4.35 Transformation temperatures of aged Cu-Al-Ni-
0.97 wt. % Mn SMA under different conditions
197
4.36 Thermodynamic parameters of Cu-Al-Ni-0.39 wt.
% Mn SMA under different aging conditions
198
4.37 Thermodynamic parameters of Cu-Al-Ni-0.71 wt.
% Mn SMA under different aging conditions
199
4.38 Thermodynamic parameters of Cu-Al-Ni-0.97 wt.
% Mn SMA under different aging conditions
199
4.39 The fracture stress-strain, microhardness and strain
recovery ratio of aged Cu-Al-Ni-0.39 wt. % Mn
SMA at different conditions
202
4.40 The fracture stress-strain, microhardness and strain
recovery ratio of aged Cu-Al-Ni-0.71 wt. % Mn
SMA at different conditions
203
xvi
4.41 The fracture stress-strain, microhardness and strain
recovery ratio of aged Cu-Al-Ni-0.97 wt. % Mn
SMA at different conditions
203
4.42 Lattice parameters of Cu-Al-Ni-0.42 wt. % Co
SMA under different aging conditions
220
4.43 Lattice parameters of Cu-Al-Ni-0.72 wt. % Co
SMA under different aging conditions
220
4.44 Lattice parameters of Cu-Al-Ni-1.14 wt. % Co
SMA under different aging conditions
220
4.45 Transformation temperatures of aged Cu-Al-Ni-
0.42 wt. % Co SMA under different conditions.
223
4.46 Transformation temperatures of aged Cu-Al-Ni-
0.72 wt. % Co SMA under different conditions.
224
4.47 Transformation temperatures of aged Cu-Al-Ni-
1.14 wt. % Co SMA under different conditions.
225
4.48 Thermodynamic parameters of Cu-Al-Ni-0.42 wt.
% Co SMA under different aging conditions
225
4.49 Thermodynamic parameters of Cu-Al-Ni-0.72 wt.
% Co SMA under different aging conditions
225
4.50 Thermodynamic parameters of Cu-Al-Ni-1.14 wt.
% Co SMA under different aging conditions
226
4.51 The fracture stress-strain, microhardness and strain
recovery ratio of aged Cu-Al-Ni-0.42 wt. % Co
SMA at different conditions.
229
4.52 The fracture stress-strain, microhardness and strain
recovery ratio of aged Cu-Al-Ni-0.72 wt. % Co
SMA at different conditions.
230
4.53 The fracture stress-strain, microhardness and strain
recovery ratio of aged Cu-Al-Ni-1.14 wt. % Co
SMA at different conditions.
230
xvii
LIST OF FIGURES
FIGURE NO TITLE PAGE
2.1 Temperature-induced phase transformation of an
SMA without mechanical loading. 12
2.2 Schematic of the shape memory effect of an
SMA showing the detwinning of the material
with an applied stress. 13
2.3 Schematic of the shape memory effect of an
SMA showing the unloading and subsequent
heating to austenite under no load condition. 14
2.4 Temperature-induced phase transformation in
the presence of applied load. 15
2.5 A pseudoelastic loading path. 16
2.6 Schematic of a pseudoelastic stress-strain
diagram. 16
2.7 Schematic of a stress-temperature phase diagram
for an SMA. 17
2.8 Stress-Temperature diagram in the martensitic and
austenitic domains. 18
2.9 Schematic diagram of stress-strain-temperature
for the involved crystallographic changes during
the phenomena of SME. 19
2.10 The two loading paths discussed for
pseudoelasticity in single crystal SMA. 21
xviii
2.11 Ternary phase diagram Cu-Al-Ni, vertical cross-
section at 3 wt. % Ni. 26
2.12 Schematic phase diagram of Cu-Al-Ni alloy in
temperature-stress coordinates. 27
2.13 Evolution of (a) DSC heating-cooling curves (b)
the Ms transformation temperature and (c) the
transformation enthalpy of the as a function of
Al content. 32
2.14 Differential scanning calorimetry profiles for
Cu-Al-Ni alloys: (a) Cu-Al-Ni; (b) Cu-Al-Ni-
0.2Ti; (c) Cu-Al-Ni-0.4 Mn;(d) Cu-Al-Ni-0.2Zr. 33
2.15 Optical micrographs for alloys: (a) Cu-9.9wt. %
Al-4.43 wt. % Ni, (b) Cu- 22.11 wt. % Al- 7..4
wt. % Ni and (c) Cu- 22.41 wt. % Al- 7..4 wt. %
Ni 35
2.16 SEM micrographs of (a) Cu-13.0Al-4Ni (b) Cu-
13.5Al-4Ni, (c) Cu-13.7Al-4Ni, and (d) Cu-
14.0Al-4Ni SMAs 36
2.17 Optical micrographs of a) Cu-1 1.85wt.% Al-
3.2wt.% Ni- 3wt.% Mn, b) Cu-11.9wt.% Al-
5wt.% Ni- 2wt.% Mn-1wt.% Ti, c) Cu-
11.4wt.% Al-2.5wt.% Ni- 5wt.% Mn-0.4wt.%
Ti, and d) Cu-1 1.8wt.% Al- 5wt.% Ni-2wt.%
Mn-1%wt.% Ti 37
2.18 Optical micrographs of Cu–Al–Ni alloys: (a)
Cu–Al–Ni; (b) Cu–Al–Ni–0.2Ti; (c) Cu–Al–Ni–
0.4Mn; (d) Cu–Al–Ni–0.2Zr 38
2.19 Variation in the (a) transition stress, (b)
fracture strain, and (c) fracture stress versus
grain size 40
2.20 Tensile fracture surfaces at room temperature for
(a) Cu-13.4Al-3.8Ni SMA, (b) Cu-13.2Al-
3.04Ni-0.36Ti SMA, (c) Cu-13.0Al-2.9Ni-0.36
xix
Ti-0.22 Mn SMA and (d) Cu-13.4Al-3.05Ni-
0.24 Ti- 0.63 Zr SMA
41
2.21 Recoverable strain vs. bend-relaxing time of Cu-
Al-Ni and Cu-Al-Ni-Be 42
2.22 Stress-strain curves of SMA samples at room
temperature (25°C) 42
2.23 Transformation temperatures of the alloy wires
treated at different thermal treatment
temperatures 45
2.24 DSC thermograms of (a) Cu–14.1Al–4.0Ni wt.
% and (b) Cu–13.4Al–4.0 Ni wt. % at different
conditions 45
2.25 Changes of transformation temperatures with
various aging times in Cu-Al-Ni alloy 47
2.26 Optical micrographs of Cu–13.4Al–4.0Ni wt. %
in the: (a) as-grown and (b) aged (523 K)
conditions 49
2.27 SEM micrographs of the aged Cu–14.1Al–4.0Ni
wt. % at: (a) 473 K and (b) 573 K 49
2.28 Structures of biphasic cell germination after 10
min (a) and 20 min (b) at 400 oC 50
2.29 The schematic process of the precipitation of
biphasic cell and nanoprecipitates at 400 oC,
with zoom of α area 50
2.30 Morphologies of γ2 phase in longitudinal cross
sections of the alloy wires treated at different
heat treatment temperatures: (a) 700 oC, (b) 730
oC, (c) 750
oC, (d) 760◦ C, (e) 770
oC, and(f) 780
oC 52
2.31 Tensile stress–strain response of (a) Cu–14.1Al–
4.0Ni wt. % and (b) Cu–13.4Al–4.0Ni wt. % in
the as-quenched and aged (at 473 K for 24 h)
conditions 54
2.32 Variation of compressive transformation stresses
Cu-14.1Al-4.0Ni wt. % and Cu-13.4Al-4.0Ni wt.
xx
% with aging 54
2.33 Figure 2.33 σ-ε curves at room temperature for
(a) aged and (b) un-aged samples 55
2.34 The variation of Vickers hardness for Cu-Al-Ni
SMA with the holding time at room temperature
a) aging at room temperature after quenching b)
aging at room temperature after annealing at 330
oC for 30 mins 56
2.35 Variation of Vickers hardness with various aging
times 56
2.36 The changes in hardness (a), electrical resistivity
(b) and transformation temperatures (c) in Cu-
11.88 wt.% Al -5.06 wt.% Ni- 1.65 wt.% Mn-
0.96 wt.%Ti alloy after aging at 250°C and
300°C 58
2.37 The changes in hardness (a), electrical resistivity
(b) and transformation temperatures (c) in Cu-
11.88 wt.% Al-5.06 wt. % Ni- 1.65wt. % Mn-
0.96 wt. %Ti alloy after aging at 350°C and
400°C 59
2.38 Scheme of a powder metallurgy method. 61
2.39 The scheme of a free jet melts spinner. 62
2.40 Operating temperature range for automobiles
applications and the transformation temperatures
for selected commercially available and
developed SMAs 64
3.1 Flow chart for the research methodology 69
3.2 Production of the cast materials (a) Schematic of
the whole process, (b) Silicon carbide crucible,
(c) Cast iron mold, (d) Cast ingot 71
3.3 Schematic of Differential scanning calorimeter
curve showing critical transformation
temperatures 77
xxi
3.4 a) Instron universal tensile testing machine, b)
schematic of tensile specimen 78
3.5 Shape memory effect test; (a) Experimental; (b)
Schematic includes (1) Un-deformed sample, (2)
Deformed sample, (3) Preheating the deformed
samples above Af, (4) Sample after recovery. 79
3.6 Schematic diagram of the aging treatment 80
4.1 Microstructure of the Cu-Al-Ni SMA; a) Optical
micrograph; b) Scanning electron micrograph. 83
4.2 SEM and EDS analysis of the Cu-Al-Ni (a)
Micrograph of scanned area; (b) Spectrum 1; (c)
Spectrum 2 84
4.3 Optical micrograph of Cu-Al-Ni SMA shows γ`1
and β`1 phase 85
4.4 X-ray diffraction patterns of Cu-Al-Ni SMA 86
4.5 TEM images corresponding with selected area
diffraction patterns of Cu-Al-Ni SMA: (a) Bright
field of TEM image, (b) HRTEM image, (c)
Selected area diffraction patterns. 87
4.6 Differential Scanning Calorimetry (DSC) curves
of the Cu-Al-Ni SMA. 88
4.7 Stress-strain curves of Cu-Al-Ni SMA obtained
from the tensile test performed at room
temperature. 91
4.8 Fracture surface of the Cu-Al-Ni SMA after
tensile test (a) Low magnification, (b) High
magnification 92
4.9 Shape memory effect curve of the Cu-Al-Ni
SMA, ε_r is residual strain; ε_p is plastic strain 94
4.10 Micrographs showing the microstructures of the
Cu-Al-Ni SMA with different concentration of
Ti additions: a,d) Cu-Al-Ni-0.37 wt. % Ti SMA,
b,e) Cu-Al-Ni-0.76 wt.% Ti SMA, c,f) Cu-Al-
xxii
Ni-0.99 wt.% Ti SMA. 97
4.11 EDS analysis of the Cu-Al-Ni-0.99 wt. % Ti
SMA (a) Micrograph of scanned area; (b)
Spectrum 1; (c) Spectrum 2. 98
4.12 X-ray diffraction patterns of a) Cu-Al-Ni-0.37
wt. % Ti, b) Cu-Al-Ni-0.76 wt. % Ti, c) Cu-Al-
Ni-0.99 wt. % Ti. 99
4.13 TEM images corresponding with selected area
diffraction patterns of Cu-Al-Ni-0.76 wt. % Ti
SMA: a) Bright field of TEM image, b) HRTEM
image, c) The selected area diffraction pattern. 102
4.14 An Elemental distribution map of Cu-Al-Ni-0.99
wt. % Ti SMA elemental, (a) Scanned area, (b)
Aluminum, (c) Titanium, (d) Nickel, and (e)
Copper distribution 103
4.15 Transformation temperature curves of the Cu-
Al-Ni SMA with different percentage of Ti
addition, (a) DSC curves, (b) Heating curve, and
(c) Cooling curve 104
4.16 Tensile stress-strain curves of Cu-Al-Ni SMA
with Ti addition 107
4.17 Fracture surfaces of the alloys: a) Cu-Al-Ni-0.37
wt. % Ti, b) Cu-Al-Ni-0.76 wt. % Ti, c) Cu-Al-
Ni-0.99 wt. % Ti. 108
4.18 Shape memory effect curves of Cu-Al-Ni-XTi
SM alloys 110
4.19 Micrographs showing the microstructures of the
Cu-Al-Ni SMA with different concentration of
Mn additions: a,d) Cu-Al-Ni-0.39 wt.% Mn, b,e)
Cu-Al-Ni-0.71 wt.% Mn, c,f) Cu-Al-Ni-0.97
wt.% Mn. 112
4.20 EDS analysis of the Cu-Al-Ni-0.97 wt. % Mn,
(a) Micrograph of scanned area; (b) Spectrum 1;
xxiii
(c) Spectrum 2, (d) Spectrum 3. 113
4.21 X-ray diffraction patterns of a) Cu-Al-Ni-0.39
wt. % Mn, b) Cu-Al-Ni-0.71 wt. % Mn, c) Cu-
Al-Ni-0.97 wt. % Mn 114
4.22 An Elemental distribution map of Cu-Al-Ni-0.97
wt. % Mn SMA elemental, (a) Scanned area, (b)
Copper, (c) Aluminium, (d) Nickel, and (e)
Manganese distribution. 116
4.23 TEM images corresponding with selected area
diffraction patterns of Cu-Al-Ni-0.71 wt.% Mn
and Cu-Al-Ni-0.97 wt. % Mn: a) Bright field of
TEM image of Cu-Al-Ni-0.71 Mn alloy, b)
HRTEM image of the Cu-Al-Ni-0.71 wt. %Mn
alloy, c) SADP of the Cu-Al-Ni-0.71 wt. %Mn
alloy, d) Bright field of TEM image of Cu-Al-
Ni-0.97 Mn alloy, e) HRTEM image of the Cu-
Al-Ni-0.97 wt. %Mn alloy, f) SADP of the Cu-
Al-Ni-0.97 wt. %Mn alloy. 117
4.24 Transformation temperature curves of the Cu-
Al-Ni SMA with different percentage of Mn
addition
120
4.25 Tensile stress-strain curves of Cu-Al-Ni SMA
with Mn addition 122
4.26 Fracture surfaces of the alloys: a) Cu-Al-Ni-0.39
wt. % Mn, b) Cu-Al-Ni-0.71 wt. % Mn, c) Cu-
Al-Ni-0.97 wt. % Mn. 123
4.27 Shape memory effect curves of the alloys at 373
K, then preheated to 676 K.. 125
4.28 Micrographs showing the microstructure of Cu-
Al-Ni SMA with different concentration of Co
additions: a,d) Cu-Al-Ni-0.42 wt. % Co, b,e) Cu-
Al-Ni-0.7 wt. % Co, c,f) Cu-Al-Ni-1.14 wt. %
Co. 128
xxiv
4.29 EDS analysis of Cu-Al-Ni-1.14 wt. % Co (a)
Micrograph of scanned area; (b) Spectrum 1; (c)
Spectrum 2. 129
4.30 Volume fraction and size of γ2 precipitates of Cu-
Al-Ni-XCo (0.42, 0.72, and 1.14 wt. %). 129
4.31 X-ray diffraction patterns of a) Cu-Al-Ni-0.42
wt. % Co, b) Cu-Al-Ni-0.72 wt. % Co, c) Cu-Al-
Ni-1.14 wt.% Co. 130
4.32 TEM images the corresponding with selected
area diffraction patterns of Cu-Al-Ni-0.72 wt. %
Co and Cu-Al-Ni-1.14 wt. % Co: a) Bright field
of TEM image of Cu-Al-Ni-0.72 wt. % Co alloy,
b) HRTEM image of the Cu-Al-Ni-0.72 wt. %
Co alloy, c) SADP of the Cu-Al-Ni-0.72 wt. %
Co alloy, d) Bright field of TEM image of Cu-
Al-Ni-1.14 wt.%. % Co alloy, e) HRTEM image
of the Cu-Al-Ni-1.14 wt. % Co alloy, f) SADP
of the Cu-Al-Ni-1.14 wt. % Co alloy. 133
4.33 An Elemental distribution map of Cu-Al-Ni-
1.14 wt.% Co SMA elemental, (a) Scanned area,
(b) Aluminium, (c) Cobalt, (d) Nickel, and (e)
Copper distribution. 135
4.34 Transformation temperature curves of the Cu-
Al-Ni SMA with different percentage of Co
addition
136
4.35 Evaluation of the martensite-austenite
transformation temperatures as a function of Co
additions 137
4.36 Tensile stress-strain curves of Cu-Al-Ni SMA
with Co addition 139
4.37 Fracture surface: a) Cu-Al-Ni SMA, b) Cu-Al-
Ni-0.42 wt. % Co SMA, b) Cu-Al-Ni-0.72 wt. %
Co SMA, c) Cu-Al-Ni-1.14 wt. % Co SMA 140
xxv
4.38 Shape memory effect curves of the Cu-Al-Ni-
XCo alloys 142
4.39 FESEM micrographs shows the microstructures
of the Cu-Al-Ni SMA under different aging
conditions: a) 373 K for 24hr, b) 373 K for 48hr,
a) 423 K for 24hr, b) 423 K for 48hr, a) 250 °C
for 24hr, b) 250 °C for 48hr. 144
4.40 EDS analysis of the Cu-Al-Ni (a) Micrograph of
scanned area; (b) Spectrum 1; (c) Spectrum 2; d)
Spectrum 3. 146
4.41 X-ray diffraction patterns of Cu-Al-Ni SMA, a)
373 K for 24hr, b) 373 K for 48hr, c) 423 K for
24hr, d) 423 K for 48hr, e) 523 K for 24hr, f)
523 K for 48hr. 147
4.42 Transformation temperature curves on the
heating and cooling cycle of the Cu-Al-Ni SMA
aged at 423 K for 24 hr. 150
4.43 Tensile stress-strain curves for the aged Cu-Al-
Ni SMA. 152
4.44 Fracture surface of Cu-Al-Ni SMA at different
aging conditions: a) 373 K for 24hr, b) 373 K for
48hr, c) 423 K for 24hr, d) 423 K for 48hr, e)
523 K for 24hr, f) 523 K for 48hr. 154
4.45 Shape memory effect curves of the aged Cu-Al-
Ni SMA 156
4.46 FESEM micrographs show the microstructures
of the Cu-Al-Ni-0.37 wt. % Ti SMA under
different aging conditions: a) 373 K for 24hr,
b)373 K for 48hr, c) 423 K for 24hr, d) 423 K
for 48hr, e) 523 K for 24hr, f)523 K for 48hr. 159
4.47 FESEM micrographs show the microstructures
of the Cu-Al-Ni-0.76 wt.% Ti SMA under
different aging conditions: a) 373 K for 24hr,
xxvi
b)373 K for 48hr, c) 423 K for 24hr, d)423 K for
48hr, e) 523 K for 24hr, f)523 K for 48hr.
160
4.48 FESEM micrographs show the microstructures
of the Cu-Al-Ni-0.99 wt.% Ti SMA under
different aging conditions: a) 373 K for 24hr, b)
373 K for 48hr, c) 423 K for 24hr, d) 423 K for
48hr, e) 523 K for 24hr, f) 523 K for 48hr. 161
4.49 X-ray diffraction patterns of Cu-Al-Ni-0.37 wt.
% Ti SMA, a) 373 K for 24hr, b)373 K for 48hr,
c) 423 K for 24hr, d)423 K for 48hr, e) 523 K for
24hr, f)523 K for 48hr. 163
4.50 X-ray diffraction patterns of Cu-Al-Ni-0.76
wt.% Ti SMA, a) 373 K for 24hr, b)373 K for
48hr, c) 423 K for 24hr, d)423 K for 48hr, e) 523
K for 24hr, f)523 K for 48hr. 164
4.51 X-ray diffraction patterns of Cu-Al-Ni-0.99
wt.% Ti SMA, a) 373 K for 24hr, b)373 K for
48hr, c) 423 K for 24hr, d)423 K for 48hr, e) 523
K for 24hr, f)523 K for 48hr. 165
4.52 Transformation temperature curves of the Cu-
Al-Ni-0.37 wt. % Ti SMA aged at 523 K for 24
hr. 168
4.53 DSC diagrams of the heating and cooling cycle
of the Cu-Al-Ni-0.76 wt.% Ti SMA aged at 523
K for 24 hr. 169
4.54 DSC diagrams of the heating and cooling cycle
of the Cu- Al- Ni- 0.99 wt.% Ti SMA aged at
523 K for 24 hr. 170
4.55 Tensile stress-strain curves for SMA: a) Cu - Al-
Ni -0.37 wt. % Ti; b) Cu -Al- Ni -0.76 wt. % Ti;
c) Cu- Al -Ni -0.99 wt. % Ti. 173
4.56 Fracture surface of Cu-Al-Ni- 0.37 wt. % Ti
SMA at different aging conditions: a) 373 K for
xxvii
24hr, b)373 K for 48hr, c) 423 K for 24hr, d)423
K for 48hr, e) 523 K for 24hr, f)523 K for 48hr.
177
4.57 Fracture surface of Cu-Al-Ni- 0.76 wt.% Ti
SMA at different aging conditions: a) 373 K for
24hr, b)373 K for 48hr, c) 423 K for 24hr, d)423
K for 48hr, e) 523 K for 24hr, f)523 K for 48hr. 178
4.58 Fracture surface of Cu-Al-Ni- 0.99 wt.% Ti
SMA at different aging conditions: a) 373 K for
24hr, b)373 K for 48hr, c) 423 K for 24hr, d)423
K for 48hr, e) 523 K for 24hr, f)523 K for 48hr. 179
4.59 SME curves of the aged Cu-Al-Ni-0.37 wt. % Ti
SMA 182
4.60 SME curves of the aged Cu-Al-Ni-0.76 wt. % Ti
SMA. 183
4.61 Shape memory effect curves of the aged Cu-Al-
Ni-0.99 wt. % Ti SMA 183
4.62 FESEM micrographs showing the
microstructures of the Cu-Al-Ni- 0.39wt. % Mn
SMA under different aging conditions: a) 373 K
for 24hr, b) 373 K for 48hr, c) 423 K for 24hr, d)
423 K for 48hr, e) 523 K for 24hr, f) 523 K for
48hr. 186
4.63 FESEM micrographs showing the
microstructures of the Cu-Al-Ni- 0.71 wt.% Mn
SMA under different aging conditions: a) 373 K
for 24hr, b) 373 K for 48hr, c) 423 K for 24hr, d)
423 K for 48hr, e) 523 K for 24hr, f) 523 K for
48hr.
187
4.64 FESEM micrographs showing the
microstructures of the Cu-Al-Ni- 0.97 wt.% Mn
SMA under different aging conditions: a) 373 K
for 24hr, b) 373 K for 48hr, c) 423 K for 24hr, d)
xxviii
423 K for 48hr, e) 523 K for 24hr, f) 523 K for
48hr.
188
4.65 X-ray diffraction patterns of aged Cu-Al-Ni-
0.39wt. % Mn SMA, a) 373 K for 24hr, b)373 K
for 48hr, c) 423 K for 24hr, d) 423 K for 48hr, e)
523 K for 24hr, f)523 K for 48hr. 189
4.66 X-ray diffraction patterns of aged Cu-Al-Ni-0.71
wt.% Mn SMA, a) 373 K for 24hr, b)373 K for
48hr, c) 423 K for 24hr, d)423 K for 48hr, e) 523
K for 24hr, f)523 K for 48hr.
190
4.67 X-ray diffraction patterns of aged Cu-Al-Ni-0.97
wt.% Mn SMA, a) 373 K for 24hr, b) 373 K for
48hr, c) 423 K for 24hr, d) 423 K for 48hr, e)
523 K for 24hr, f) 523 K for 48hr. 191
4.68 DSC diagrams on the heating and cooling cycle
of the Cu-Al-Ni-0.39 wt. % Mn SMA aged at
523 K for 24hr. 195
4.69 DSC diagrams on the heating and cooling cycle
of the Cu-Al-Ni-0.71 wt. % Mn SMA aged at
523 K for 24hr. 196
4.70 DSC diagrams on the heating and cooling cycle
of the Cu-Al-Ni-0.97 wt. % Mn SMA aged at
523 K for 24hr. 197
4.71 Tensile stress-strain curves for SMA: a) Cu - Al-
Ni-0.39 wt. % Mn; b) Cu-Al-Ni-0.71 wt.% Mn;
c) Cu- Al -Ni -0.97 wt. % Mn. 202
4.72 Fracture surface of the aged Cu-Al-Ni-0.39wt. %
Mn SMA at different aging conditions: a) 373 K
for 24hr, b) 373 K for 48hr, c) 423 K for 24hr, d)
423 K for 48hr, e) 523 K for 24hr, f) 523 K for
48hr.
205
4.73 Fracture surface of the aged Cu-Al-Ni-0.71 wt.%
Mn SMA at different aging conditions: a) 373 K
xxix
for 24hr, b) 373 K for 48hr, c) 423 K for 24hr, d)
423 K for 48hr, e) 523 K for 24hr, f) 523 K for
48hr.
206
4.74 Fracture surface of the aged Cu-Al-Ni-0.97 wt.%
Mn SMA at different aging conditions: a) 373 K
for 24hr, b)373 K for 48hr, c) 423 K for 24hr,
d)423 K for 48hr, e) 523 K for 24hr, f)523 K for
48hr. 207
4.75 SME curves of the aged Cu-Al-Ni-0.39wt. %
Mn SMA
208
4.76 SME curves of the aged Cu-Al-Ni-0.71 wt. %
Mn SMA 208
4.77 SME curves of the aged Cu-Al-Ni-0.97 wt. %
Mn SMA 209
4.78 FESEM micrographs showing the
microstructures of the Cu-Al-Ni-0.42 wt. % Co
SMA under different aging conditions: a) 373 K
for 24hr, b) 373 K for 48hr, c) 423 K for 24hr, d)
423 K for 48hr, e) 523 K for 24hr, f) 523 K for
48 hr. 213
4.79 FESEM micrographs showing the
microstructures of the Cu-Al-Ni-0.72 wt. % Co
SMA under different aging conditions: a) 373 K
for 24hr, b) 373 K for 48hr, c) 423 K for 24hr, d)
423 K for 48hr, e) 523 K for 24hr, f) 523 K for
48 hr. 214
4.80 FESEM micrographs showing the
microstructures of the Cu-Al-Ni-1.14 wt. % Co
SMA under different aging conditions: a) 373 K
for 24hr, b) 373 K for 48hr, c) 423 K for 24hr, d)
423 K for 48hr, e) 523 K for 24hr, f) 523 K for
48 hr.
215
4.81 X-ray diffraction patterns of Cu-Al-Ni-0.42 wt.
xxx
% Co SMA, a) 373 K for 24hr, b) 373 K for
48hr, c) 423 K for 24hr, d)423 K for 48hr, e) 523
K for 24hr, f) 523 K for 48hr.
217
4.82 X-ray diffraction patterns of Cu-Al-Ni-0.72
wt.% Co SMA, a) 373 K for 24hr, b) 373 K for
48hr, c) 423 K for 24hr, d)423 K for 48hr, e) 523
K for 24hr, f)523 K for 48hr. 218
4.83 X-ray diffraction patterns of Cu-Al-Ni-1.14
wt.% Co SMA, a) 373 K for 24hr, b) 373 K for
48hr, c) 423 K for 24hr, d)423 K for 48hr, e) 523
K for 24hr, f)523 K for 48hr. 219
4.84 DSC diagrams on the heating and cooling cycle
of the Cu-Al-Ni-0.42 wt. % Co SMA aged at
523 K for 24 hr. 222
4.85 DSC diagrams on the heating and cooling cycle
of the Cu-Al-Ni-0.72 wt.% Co SMA aged at 523
K for 24 hr. 223
4.86 DSC diagrams on the heating and cooling cycle
of the Cu-Al-Ni-1.14 wt.% Co SMA aged at 523
K for 24 hr. 224
4.87 Tensile stress-strain curves for SMA: a) Cu - Al-
Ni -0.42 wt. % Co; b) Cu -Al- Ni -0.72 wt. %
Co; c) Cu- Al -Ni -1.14 wt. % Co. 228
4.88 Fracture surface of Cu-Al-Ni-0.42 wt. % Co
SMA at different aging conditions: a) 373 K for
24hr, b)373 K for 48hr, c) 423 K for 24hr, d)423
K for 48hr, e) 523 K for 24hr, f)523 K for 48hr. 232
4.89 Fracture surface of Cu-Al-Ni-0.72 wt.% Co
SMA at different aging conditions: a) 373 K for
24hr, b)373 K for 48hr, c) 423 K for 24hr, d)423
K for 48hr, e) 523 K for 24hr, f)523 K for 48hr.
233
4.90 Fracture surface of Cu-Al-Ni-1.14 wt.% Co
SMA at different aging conditions: a) 373 K for
xxxi
24hr, b)373 K for 48hr, c) 423 K for 24hr, d)423
K for 48hr, e) 523 K for 24hr, f)523 K for 48hr.
234
4.91 SME curves of the aged Cu-Al-Ni-0.42 wt. %
Co SMA. 236
4.92 SME curves of the aged Cu-Al-Ni-0.72 wt. %
Co SMA. 237
4.93 SME curves of the aged Cu-Al-Ni-1.14 wt. %
Co SMA. 237
4.94 DSC curves of the Cu-Al-Ni SMA with and
without addition of alloying elements (a) heating
and (b) cooling 240
4.95 Shape memory effect curves of the modified and
unmodified alloys before aging treatment 242
4.96 Shape memory effect curves of the modified and
unmodified alloys after aging treatment 242
xxxii
LIST OF ABBREVIATIONS
Cu-Al-Ni - Copper Aluminum Nickel
DSC - Differential scanning calorimetry
EDS - Energy dispersive spectroscopy
FE-SEM - Field emission scanning electron microscopy
HRTEM - High resolution transmission electron microscopy
ICP-MS - Inductive couple plasma- mass spectroscopy
OM - Optical microscope
SADP - Selected area diffraction pattern
SEM - Scanning electron microscopy
SMAs - Shape memory alloys
SME - Shape memory effect
TEM - Transmission electron microscopy
XRD - X-ray diffraction
xxxiii
LIST OF SYMBOLS
(hkl) - Miller indices
- Enthalpy of Martensite → Austenite
- Enthalpy of Austenite → Martensite
- Entropy of Martensite → Austenite
- Entropy of Austenite → Martensite
- Fracture strain
- Strain after heating above Af
- Residual strain
- Strain recovery ratio by shape memory effect
- Fracture stress
a, b, and c - Lattice parameters
a.u - arbitrary unit
Af - Austenite finish temperature
As - Austenite start temperature
B - Full width at half maximum
d - Spacing distance
G - Gibbs free energy
Hv - Vicker‟s hardness
K/min - Kelvin per minute
Mf - Martensite finish temperature
Ms - Martensite start temperature
oC - Centigrade degree
T - Temperature
To - Equilibrium temperature
xxxiv
Wt.% - Weight percentage
α, β - Lattice angles
θ - Bragg‟s angle
λ - Wavelength
G.B - Grain boundary
xxxv
LIST OF APPENDICES
APPENDIX TITLE PAGE
A DSC curves of the aged Cu-Al-Ni-Xy (X is Ti,
Mn, and Co; y is weight percentage)
267
B Publications 277
1
CHAPTER 1
INTRODUCTION
1.1 Background of Research
Shape memory alloys (SMAs) and their associated thermoelastic martensitic
transformation have been the subject of extensive studies for many years, since they
have many technological applications utilizing the shape memory effect [1, 2].
Typical for shape memory material is a unique, unconventional correlation of
temperature, stress and strain that crystallographic reversible thermo-elastic
martensitic transformation forms its basis. Since technological applications impose
reliability requirements on commercial SMAs, the MT (martensitic transformation)
in particular need to be highly reproducible [3]. As a result, controlling the
martensite type and the MT temperatures becomes a basic point for determining the
SMA‟s thermo-mechanical and hysteresis properties. Since extreme sensitivity is
shown towards concentration changes by MT temperatures, controlling quaternary or
ternary alloys‟ concentration with a lot of precision is difficult as the composition of
the alloy is very vital in the determination of the MT temperatures. Parameters such
as structure ordering and grain size are depended upon by phase transformation
temperatures but their importance can not be compared to that of the alloy
composition. It is also worthy to note that the martensite type which is obtained is
dependent of the intermetallic alloy‟s degree of order [4] that also is independent of
2
the concentration of the alloy [5].
When compared to the many SMAs which are available, the most
commercially attractive alloys which can be employed in applications which are
practical are the Cu-based SMAs. That is because they exhibit reasonable shape
memory effect, offer the possibility of being used at high temperatures, have better
thermal stability and are not expensive. It should also be noted that the Cu-Al-Ni
alloys‟ applications have restrictions since they are associated with brittle inter-
granular cracking and poor workability and thus used where very small shape
changes are required [6]. Their grain size which is large (1-3 mm), high elastic
anisotropy ratio (~14) and the high degree of order which they are associated with is
responsible for the material failure through inter-granular fracture which they exhibit
[7-9]. The difficulty of stress concentration is enhanced by these factors at the grain
boundaries and as a result promoting fracture. Hence, poor mechanical properties are
exhibited by these alloys (fracture strain 0.5% and fracture stress 150 MPa). It has
been established by Husain [10] and Sugimoto et al [11] that within Cu-Al-Ni shape
memory alloys with a basis on β when subjected to stress, the existent elastic
anisotropy within the allows is responsible the polycrystalline samples‟ stress
concentration at the grain boundaries. High stress concentration can result due to the
large grain size. The martensitic strain‟s orientation dependence also determines the
elastic anisotropy. The alloys‟ stress relaxation properties can also be reduced by the
spinodal transformation and the existent ordered phases [12, 13].
Research work pertaining to Cu-Al-Ni SMAs is of considerable significance
since these alloys possess higher transformation temperatures [14] and higher
damping capacity [15, 16], especially at high temperatures, compared with even
Nitinol. That makes them to be well suited when being employed in engineering
applications like actuators. They fit well in actuators that operate within high
temperatures, bridges‟ damping elements, buildings, oil well applications and other
structures. It should be remembered that when Cu-Al-Ni alloys are subjected to very
high temperature service conditions, they show some susceptibility to post-quench
aging and as a result lead to a change in their mechanical properties, martensitic
phases and transformation temperatures with the time of operation [17, 18].
3
The material‟s deformation within the martensitic state (below Mf) is
influenced by the shape memory effect. A number of effects can take place over the
deformation which may lead the macroscopic shape change within Cu-Al-Ni SMAs.
Usually, self-accommodating plate variants are contained within the thermoelastic
martensitic structure. The variants rearrange and coalesce through the intervenient
boundaries‟ movement when the deformation takes place. Development of
mechanical twins may take place during this process. As a result, in response to the
stress which is applied, formation of the most favorably oriented martensite variants
occur. Additionally, when responding to the deformation, martensite → martensite
transformations which involve changes in the stacking sequence form: taking place
of austenite → martensite transformations occurs[19, 20]. There have been wide
studies regarding ro the Cu-Al-Ni SMAs‟ shape memory effect within the bending
test [20-22] though not much has been done when studies these properties under the
tensile test [23, 24].
A number of attempts have been made in improving mechanical properties.
Ductility is the property within Cu–Al–Ni SMAs that has been put into consideration
by using different techniques to do grain refining such as adding small amounts of
quaternary elements, such as Zr, V and Ti and including aging treatment [22, 25-28].
Though properties like ductility and strength were improved after that, some
mechanical properties still remained unsatisfactory to be used for some targeted
commercial applications more so when a full shape recovery was necessary. A
number of studies have been done on different aging aspects of the alloys and the
influence they have on their shape memory properties [17]. The martensite
stabilization phenomenon was given special attention since it is normally associated
the reverse transformation temperatures (As and Af)‟s increase once deformation has
taken place. Though, not many studies were done on the aged alloys‟ thermo-
mechanical response [23, 29, 30]. Thus, this research aims to study the effect of
alloying elements and aging treatments on the phase transformation behavior and
properties of Cu-Al-Ni SMAs.
4
1.2 Problem Statement
Since Cu-Al-Ni shape memory alloy has many advantages, which has attracted
more attention from the scientists and researchers, their applications are limited due
to the low recovery strain and high brittleness. Their damaging properties may be
improved by adding specific alloying elements followed by aging treatments. An
investigation into the structure and property relationship is necessary to ensure the
correct compositions of Cu-Al-Ni SMAs, which gives the optimum performance that
can achieve 100 % of the shape recovery.
1.3 Purpose of the Research
The purpose of this research is to find ways to improve the poor properties of
Cu-Al-Ni SMA in terms of its low recovery strain (40-50 %) and high brittleness (1-
1.2% fracture strain). The research induces understanding the mechanisms and
transformation behavior of the Cu-Al-Ni SMAs and identifies the influence of
alloying elements on the structure and properties of the alloys. The output of this
research is expected to improve the mechanical properties and reduce the limitation
usage for many industrial applications, e.g., actuators and sensors that will be helpful
to prevent the destruction of such structures as buildings and bridges. The effect of
various alloying materials such as Mn, Co, and Ti with different additions amounts
along with applying different aging conditions of 373 K, 423 K, and 523 K for 24
and 48 hr on the phase transformation behavior of Cu-Al-Ni SMAs are investigated
using various material characterization techniques. This study is expected to provide
the phase transformation characteristics of each alloy in accordance with their
microstructural observations, transformation temperatures and mechanical properties
such as tensile, shape memory effect, and hardness.
5
1.4 Objectives of the Research
The objectives of the research are as follows:
1. To determine the effect of different amounts of alloying elements (Ti,
Mn, and Co) on the structure and properties of the Cu-Al-Ni shape
memory alloys.
2. To investigate the effects of aging temperature and aging time on the
structure and properties of Cu-Al-Ni shape memory alloys.
3. To establish the correlation between the phase transformation
characteristics of Cu-Al-Ni SMA, with respect to the concentration of
alloying elements and aging treatment.
1.5 Scopes of the Research
The scope of the research is as follows:
1. Preparation of the samples by casting commercially pure raw metals (Cu
99.999 %, Al 99.999, and Ni 99.995 %) with and without alloying
elements e.g., Ti 99.99 %, Mn 99.99%, and Co 99.95% by using an
induction furnace.
2. Analysis of the as-cast samples by using inductively coupled plasma mass
spectrometry (ICP-MS) for composition analysis, differential scanning
calorimetry (DSC) for phase transformation temperature, and Vicker‟s
test for hardness measurement.
3. Aging treatment of the as-cast samples under different condition of
temperature and time.
4. Microstructural and phase analysis of the as-cast and aged samples using
field emission scanning electron microscopy (FESEM), X-ray diffraction
6
(XRD), and energy dispersive spectroscopy (EDS).
5. Perform the tensile test on the as-cast and aged samples in order to
determine the fracture stress and strain by using an Instron 5982-type
universal testing machine.
6. Perform shape memory test on the as-cast and aged samples using
specially designed tensile test machine.
7. Detailed analysis of selected samples after shape memory test by using
transmission electron microscope (TEM).
1.6 Significance of the Research
The basic aim of this research is to provide significant information on the
behavior of the Cu-Al-Ni SMAs with and without alloying addition and aging
treatments. Thus, the results of this research will benefit the automotive, civil and
aerospace industries using the shape memory alloys in terms of improved properties
such as ductility and reduction in brittleness. However, it gives the allowance for
these materials to be used for higher temperatures without losing its shape memory
effect. In addition, the outcomes of this research will contribute to providing a
sustainable material with better properties and extensive earthquake applications.
246
REFERENCES
1. Sarı, U. and Kırındı, T. Effects of deformation on microstructure and
mechanical properties of a Cu–Al–Ni shape memory alloy. Materials
Characterization. 2008. 59(7): 920-929.
2. Saburi, T. and Wayman, C. M. Crystallographic similarities in shape memory
martensites. Acta Metallurgica. 1979. 27(6): 979-995.
3. Recarte, V., Pérez-Sáez, R. B., San Juan, J., Bocanegra, E. H. and Nó, M. L.
Influence of Al and Ni concentration on the Martensitic transformation in Cu-
Al-Ni shape-memory alloys. Metallurgical and Materials Transactions A.
2002. 33(8): 2581-2591.
4. V Recartea, b, R.B Pérez-Sáeza, E.H Bocanegrac, M.L Nóc, J San Juan.
Dependence of the martensitic transformation characteristics on
concentration in Cu–Al–Ni shape memory alloys. Materials Science and
Engineering A. 1999. 273–275: 380-384.
5. Recarte, V., Lambri, O., Pérez-Sáez, R., Nó, M. and San Juan, J. Ordering
temperatures in Cu–Al–Ni shape memory alloys. Applied physics letters.
1997. 70(26): 3513-3515.
6. Wei, Z., Peng, H., Yang, D., Chung, C. and Lai, J. Reverse transformations in
CuAlNiMnTi alloy at elevated temperatures. Acta materialia. 1996. 44(3):
1189-1199.
7. Ma, J., Karaman, I. and Noebe, R. D. High temperature shape memory alloys.
International Materials Reviews. 2010. 55(5): 257-315.
8. Vajpai, S., Dube, R. and Sangal, S. Application of rapid solidification powder
metallurgy processing to prepare Cu–Al–Ni high temperature shape memory
alloy strips with high strength and high ductility. Materials Science and
Engineering: A. 2013. 570: 32-42.
9. Otsuka, K. and Wayman, C. M. Shape memory materials: Cambridge
university press. 1999.
247
10. Husain, S. and Clapp, P. The intergranular embrittlement of Cu-AI-Ni β-
phase alloys. Journal of materials science. 1987. 22(7): 2351-2356.
11. Sugimoto, K., Kamei, K., Matsumoto, H., Komatsu, S., Akamatsu, K. and
Sugimoto, T. Grain-refinement and the related phenomena in quaternary Cu-
Al-Ni-Ti shape memory alloys. Le Journal de Physique Colloques. 1982.
43(C4): C4-761-C764-766.
12. Zhao, J.-C. and Notis, M. Spinodal decomposition, ordering transformation,
and discontinuous precipitation in a Cu–15Ni–8Sn alloy. Acta materialia.
1998. 46(12): 4203-4218.
13. Sampath, V. Studies on the effect of grain refinement and thermal processing
on shape memory characteristics of Cu–Al–Ni alloys. Smart Materials and
Structures. 2005. 14(5): S253-S260.
14. T.W.Duerig, K. N. M., D. Stoeckel and C.M. Wayman Engineering aspects
of shape memory alloys. Materials & Design. 1990. 11(6): 301.
15. Van Humbeeck, J. and Stalmans, R. Shape Memory Alloys, Types and
Functionalities. Encyclopedia of Smart Materials: John Wiley & Sons, Inc.
2002.
16. Van Humbeeck, J. Damping capacity of thermoelastic martensite in shape
memory alloys. Journal of Alloys and Compounds. 2003. 355(1): 58-64.
17. Suresh, N. and Ramamurty, U. Aging response and its effect on the
functional properties of Cu–Al–Ni shape memory alloys. Journal of Alloys
and Compounds. 2008. 449(1-2): 113-118.
18. Suresh, N. and Ramamurty, U. Effect of aging on mechanical behavior of
single crystal Cu–Al–Ni shape memory alloys. Materials Science and
Engineering: A. 2007. 454-455: 492-499.
19. Saburi, T., Wayman, C., Takata, K. and Nenno, S. The shape memory
mechanism in 18R martensitic alloys. Acta Metallurgica. 1980. 28(1): 15-32.
20. Otsuka, K., Sakamoto, H. and Shimizu, K. Successive stress-induced
martensitic transformations and associated transformation pseudoelasticity in
Cu-Al-Ni alloys. Acta Metallurgica. 1979. 27(4): 585-601.
21. Morris, M. High temperature properties of ductile Cu-Al-Ni shape memory
alloys with boron additions. Acta metallurgica et materialia. 1992. 40(7):
1573-1586.
22. Morris, M. A. and Lipe, T. Microstructural influence of Mn additions on
248
thermoelastic and pseudoelastic properties of Cu-Al-Ni alloys. Acta
Metallurgica et Materialia. 1994. 42(5): 1583-1594.
23. Picornell, C., Pons, J. and Cesari, E. Stabilisation of martensite by applying
compressive stress in Cu-Al-Ni single crystals. Acta Materialia. 2001. 49(20):
4221-4230.
24. Sittner, P., Novak, V. and Zárubová, N. Martensitic transformations in [001]
CuAlZnMn single crystals. Acta materialia. 1998. 46(4): 1265-1281.
25. J. S. Lee; C. M. Wayman. Grain refinement of a Cu-Al-Ni shape memory
alloys by Ti and Zr additions. transactions of Japan institute of metals. 1986.
27(8): 584 -591.
26. Gao, Y., M. Zhu, J. K. L. Lai Microstructure characterization and effect of
thermal cycling and ageing on vanadium-doped Cu-Al-Ni-Mn high-
temperature shape memory alloy Journal of Materials Science. 1998. 33:
3579-3584.
27. Bhattacharya B, Bhuniya A and Banerjee M K. Influence of minor additions
on characteristics of Cu–Al–Ni alloy”, Mater. Sci. Technol. 1993. 9: 654–
658.
28. Roh, D. W., Lee, E. S. and Kim, Y. G. Effects of ordering type and degree on
monoclinic distortion of 18R-type martensite in Cu-Zn-Al alloys.
Metallurgical Transactions A. 1992. 23(10): 2753-2760.
29. S. Sugimoto, H. S., T. Hara and H. Tsuchiya The effect of grain constraint,
heat treatment and compositional change on the behavior of martensitic
transformations in alloys with the composition near Cu-13Al-4Ni-1Zn
(mass%). J. Phys. IV 1995. 5: 925.
30. Sakamoto, H. and Shimizu, K. i. Effect of Heat Treatments on Thermally
Formed Martensite Phases in Monocrystalline Cu–Al–Ni
Shape Memory Alloy. ISIJ International. 1989. 29(5): 395-404.
31. Gandhi, V. and Thompson, B. D. Smart Materials and Structures: Springer.
1992.
32. K. Otsuka, C. M. Wayman. Shape Memory Materials, reprint, illustrated ed.:
Cambridge University Press. 1999.
33. Olson, G. and Cohen, M. Stress-assisted isothermal martensitic
transformation: application to TRIP steels. Metallurgical Transactions A.
1982. 13(11): 1907-1914.
249
34. Vokoun, D. and Kafka, V. Mesomechanical modeling of shape memory
effect. Proceedings of the 1999 Symposium on Smart Structures and
Materials: International Society for Optics and Photonics. 596-601.
35. Kumar, P. and Lagoudas, D. Introduction to shape memory alloys: Springer.
2008.
36. Wayman, C. and Bhadeshia, H. Phase transformations, nondiffusive. Physical
Metallurgy. 1983. 2: 1507-1554.
37. Nishiyama, Z., Fine, M. E. and Wayman, C. M. Martensitic transformation:
Academic Press. 1978.
38. Popov, P. A. Constitutive modelling of shape memory alloys and upscaling of
deformable porous media. Texas A&M University; 2005.
39. Patoor, E., Lagoudas, D. C., Entchev, P. B., Brinson, L. C. and Gao, X. Shape
memory alloys, Part I: General properties and modeling of single crystals.
Mechanics of Materials. 2006. 38(5): 391-429.
40. Ölander, A. An electrochemical investigation of solid cadmium-gold alloys.
Journal of the American Chemical Society. 1932. 54(10): 3819-3833.
41. Greninger AB, M. V. Strain Transformation in Metastable Beta Copper-Zinc
and Beta Copper-Ti Alloys. Transactions of the Metallurgical Society of
AIME. 1938. 128: 337–368.
42. Kurdjumov GV, K. L. First reports of the thermoelastic behaviour of the
martensitic phase of Au-Cd alloys. Doklady Akademii Nauk. 1949. 66: 211-
213
43. Chang LC, Read TA.. Behavior of the elastic properties of AuCd. .
Trans Met Soc AIME. . 1951. 191(1): 47-52.
44. Kauffman, G. and Mayo, I. The Story of Nitinol: The Serendipitous
Discovery of the Memory Metal and Its Applications. The Chemical
Educator. 1997. 2(2): 1-21.
45. Buehler, W. J., Gilfrich, J. and Wiley, R. Effect of Low‐Temperature Phase
Changes on the Mechanical Properties of Alloys near Composition TiNi.
Journal of Applied Physics. 2004. 34(5): 1475-1477.
46. Van Humbeeck, J. Non-medical applications of shape memory alloys.
Materials Science and Engineering: A. 1999. 273–275(0): 134-148.
47. Sun, L., Huang, W., Ding, Z., Zhao, Y., Wang, C., Purnawali, H. and Tang,
C. Stimulus-responsive shape memory materials: a review. Materials &
250
Design. 2012. 33: 577-640.
48. Sreekumar, M., Nagarajan, T., Singaperumal, M., Zoppi, M. and Molfino, R.
Critical review of current trends in shape memory alloy actuators for
intelligent robots. Industrial Robot: An International Journal. 2007. 34(4):
285-294.
49. Baz, A., Imam, K. and McCoy, J. Active vibration control of flexible beams
using shape memory actuators. Journal of Sound and Vibration. 1990. 140(3):
437-456.
50. Duerig, T. W., Melton, K. N., Stockel, D. and Wayman, C. M. Engineering
Aspects of Shape Memory Alloys: Books on Demand. 1990.
51. Hirose, S., Ikuta, K. and Umetani, Y. Development of shape-memory alloy
actuators. Performance assessment and introduction of a new composing
approach. Advanced Robotics. 1988. 3(1): 3-16.
52. Karhu, M. and Lindroos, T. Long-term behaviour of binary Ti–49.7 Ni (at.%)
SMA actuators-the fatigue lives and evolution of strains on thermal cycling.
Smart Materials and Structures. 2010. 19(11): 115019.
53. Choon, T. W., Salleh, A. S., Jamian, S. and Ghazali, M. Phase
Transformation Temperatures for Shape Memory Alloy Wire. Enformatika.
2007. 19.
54. Ren, J. and Liew, K. Meshfree modelling and characterisation of
thermomechanical behaviour of NiTi alloys. Engineering analysis with
boundary elements. 2005. 29(1): 29-40.
55. Wada, K. and Liu, Y. Shape recovery of NiTi shape memory alloy under
various pre-strain and constraint conditions. Smart materials and structures.
2005. 14(5): S273.
56. Otsuka, K., A. Saxena, J. Deng and Xiaobing Ren Mechanism of the shape
memory effect in martensitic alloys: an assessment. Philosophical Magazine.
2011. 91(36): 4514-4535.
57. Otsuka, K. and Shimizu, K. Pseudoelasticity and shape memory effects in
alloys. International Metals Reviews. 1986. 31(1): 93-114.
58. Otsuka, K. a. X. R. Martensitic transformations in nonferrous shape memory
alloys. Materials Science and Engineering: A. 1999. 273–275(0): 89-105.
59. Macqueron, J., Morin, M., Guénin, G., Planes, A., Elgueta, J. and Castan, T.
Atomic Ordering and Martensitic Transition in a Cu-Zn-Al Shape Memory
251
Alloy. Le Journal de Physique IV. 1991. 1(C4): C4-259-C254-263.
60. Delaey, L. Diffusionless transformations. . In: Cahn, R. W., Haasen, P.,
Kramen, E.J. (Eds.), . ed. Phase Transformations in Materials, Material
Science and Technologies,. New York: VCH Publishers. 339–404; 1990.
61. Tong, H. and Wayman, C. Characteristic temperatures and other properties of
thermoelastic martensites. Acta Metallurgica. 1974. 22(7): 887-896.
62. Lagoudas, D.C. Shape Memory Alloys: Modeling and Engineering
Applications: Springer. 2008.
63. D.C.Lagoudas Shape Memory Alloys and Engineering Applications:
Springer, New York. 2008.
64. Buehler, W. J., Gilfrich, J.V., Wiley, R.C. Effects of low temperature phase
changes on the mechanical properties of alloys near composition TiNi.
Journal of Applied Physics. 1963. 34: 1475.
65. Buehler, W. J., Wiley, R.C., and 3, 851. Nickel-base alloys. 1965.
66. Jackson, C., Wagner, H. and Wasilewski, R. 55-nitinol-the alloy with a
memory: it's physical metallurgy, properties, and application. NASA Report
SP5110. 1972.
67. Melton, K. Ni-Ti Based Shape Memory Alloys. Butterworth-Heinemann,
Engineering Aspects of Shape Memory Alloys(UK), 1990. 1990: 21-35.
68. Lindquist, P. and Wayman, C. Shape Memory and Transformation Behavior
of Martensitic Ti-Pd--Ni and Ti-Pt-Ni Alloys. Butterworth-Heinemann,
Engineering Aspects of Shape Memory Alloys(UK), 1990. 1990: 58-68.
69. Strnadel, B., Ohashi, S., Ohtsuka, H., Miyazaki, S. and Ishihara, T. Effect of
mechanical cycling on the pseudoelasticity characteristics of Ti-Ni and Ti-Ni-
Cu alloys. Materials Science and Engineering: A. 1995. 203(1): 187-196.
70. Xu, Y., Shimizu, S., Suzuki, Y., Otsuka, K., Ueki, T. and Mitose, K.
Recovery and recrystallization processes in Ti-Pd-Ni high-temperature shape
memory alloys. Acta materialia. 1997. 45(4): 1503-1511.
71. Miyazaki, S. Medical and dental applications of shape memory alloys:
Cambridge: Cambridge University Press. 1999.
72. Tsunehiko Todoroki and Hirokazu Tamura. The Stress-induced
Transformation of a Ti-Ni Alloy by the Pre-load Test Method. J. Japan Inst.
Metals. 1986. 50(6): 546-554.
73. Saburi, T., Nenno, S., Nishimoto, Y. and Zeniya, M. Effects of Thermo-
252
Mechanical Treatment on the Shape Memory Effect and the Pseudoelasticity
of Ti--50. 2 Ni and Ti-47. 5 Ni--2. 5 Fe Alloys. Tetsu-to-Hagane(J. Iron Steel
Inst. Jpn.). 1986. 72(6): 571-578.
74. Saburi, T. Ti-Ni shape memory alloys. Shape memory materials. 1999: 49-
96.
75. Tadaki, T. Cu-based shape memory alloys. Shape memory materials. 1998:
97-116.
76. Miyazaki, S., Kawai, T. and Otsuka, K. Study of fracture in Cu-Al-Ni shape
memory bicrystals. Le Journal de Physique Colloques. 1982. 43(C4): C4-
813-C814-818.
77. Horikawa, H., Ichinose, S., Morii, K., Miyazaki, S. and Otsuka, K.
Orientation dependence of β1→ β1′ stress-induced martensitic transformation
in a Cu-AI-Ni alloy. Metallurgical Transactions A. 1988. 19(4): 915-923.
78. Eisenwasser, J. and Brown, L. Pseudoelasticity and the strain-memory effect
in Cu-Zn-Sn alloys. Metallurgical Transactions. 1972. 3(6): 1359-1363.
79. Lexcellent, C. Shape-Memory Alloys Handbook: Wiley. 2013.
80. Maki, T. Ferrous shape memory alloys. Shape Memory Materials. 1999: 117-
132.
81. Chakravorty, S. and Wayman, C. The thermoelastic martensitic
transformation inβ′ Ni-Al alloys: I. Crystallography and morphology.
Metallurgical Transactions A. 1976. 7(4): 555-568.
82. Ishida, K., Kainuma, R., Ueno, N. and Nishizawa, T. Ductility enhancement
in NiAl (β2)-base alloys by microstructural control. Metallurgical
Transactions A. 1991. 22(2): 441-446.
83. He, Z.-R. and Zhou, J.-E. Comparative study of martensitic transformation
behavior of NiAlMn and NiAlMnFe high temperature shape memory alloys.
Materials Science and Engineering: A. 2003. 360(1): 183-190.
84. Donkersloot, H. and Van Vucht, J. Martensitic transformations in gold-
titanium, palladium-titanium and platinum-titanium alloys near the
equiatomic composition. Journal of the Less Common Metals. 1970. 20(2):
83-91.
85. N. F. Kennon and D. P. Dunne. Shape Strains Associated with Thermally-
Induced And Stress-Induced Martensite In A Cu-Al-Ni Shape Memory Alloy.
Acta Metall. 1982. 30: 429-435.
253
86. Chen, Y., Zhang, X., Dunand, D. C. and Schuh, C. A. Shape memory and
superelasticity in polycrystalline Cu–Al–Ni microwires. Applied Physics
Letters. 2009. 95(17): 171906.
87. Miyazaki, S and M. Fremond. Shape memory alloys. International Centre for
Mechanical Sciences: Springer. 1996.
88. Zhang Xiangyang, S. Q., Yu Shouwen A non-invariant plane model for the
interface in CuAlNi single crystal shape memory alloys. Journal of the
Mechanics and Physics of Solids. 2000. 48: 2163–2182.
89. Nó, M. L., Caillard, D. and San Juan, J. A TEM study of martensite habit
planes and orientation relationships in Cu–Al–Ni shape memory alloys using
a fast Δg-based method. Acta Materialia. 2009. 57(4): 1004-1014.
90. Qiao, L., Rimoli, J., Chen, Y., Schuh, C. and Radovitzky, R. Nonlocal
Superelastic Model of Size-Dependent Hardening and Dissipation in Single
Crystal Cu-Al-Ni Shape Memory Alloys. Physical Review Letters. 2011.
106(8).
91. Xu, J. W. Effects of Gd addition on microstructure and shape memory effect
of Cu–Zn–Al alloy. Journal of Alloys and Compounds. 2008. 448(1-2): 331-
335.
92. H. Morawiec, J. L., D. Stró ˙z, M. Gigla Structure and properties of melt-
spun Cu–Al–Ni shape memory alloys. Materials Science and Engineering A.
1999. 275: 708-712.
93. Castro, M. L. a. R. R. Isothermal decomposition of some β Cu-Zn-Al alloys
with e/a=1.48. Materials Science and Engineering A 1999. 273-275:: 577-
580.
94. Dvorack, M. A. a. H. C. Thermal diffuse scattering in β-phase CuAlNi alloy.
Scripta Metallurgica. 1983. 17: 131-134.
95. Zhang, S. Cu-based shape memory powder preparation using the mechanical
alloying technique. Materials Science and Engineering A. 1993. 171: 257-
262.
96. M. Morin, F. T. Influence of thermal cycling on the reversible martensitic
transformation in a Cu-A1-Ni shape memory alloy. Materials Science and
Engineering A. 1995. 196: 177-181.
97. Na, Wpływ Szybkości Obrotowej Bębna Chłodzącego, Formowanie Się
Tekstury W. Stopach Na, and Bazie. Effect of wheel velocity on texture
254
formation and shape memory in Cu-Al-Ni based melt-spun ribbons. Archives
of Metallurgy and Materials. 2009. 54(3).
98. Pelosin, V. and A. Rivière. Structural and mechanical spectroscopy study of
the β′1 martensite decomposition in Cu-12% Al-3% Ni(wt.%) alloy Journal
of Alloys and Compounds. 1998. 268((1-2)): 166-172.
99. Z.G. Wei, H.Y. Peng, D.Z. Yang, C.Y. Chung, J.K.L. Lai. Reverse
transformations in CuA1NiMnTi alloy at elevated temperatures. Acta
Materialia. 1996. 44(3): 1189-1199.
100. Pelosin, V. and Rivière, A. NiTi and CuAlNi Martensite Studied by
Isothermal Mechanical Spectroscopy. J. Phys. IV France. 1997. 07(C5): C5-
567-C565-572.
101. Recarte, V., Pérez-Sáez, R., Bocanegra, E., Nó, M. and San Juan, J.
Dependence of the martensitic transformation characteristics on
concentration in Cu–Al–Ni shape memory alloys. Materials Science and
Engineering: A. 1999. 273: 380-384.
102. Y. Itsumi, Y. M., T. Takashima, Kazuhito Kamei, Kazuko Sugimoto The
Effects of Ageing on the Martensitic Transformation Temperature in Cu-Al-
Ni-Mn-Ti Shape Memory Alloys. Advanced Materials Research. 1991. 56-
58: 469-474.
103. Karagoz, Z. and Canbay, C. A. Relationship between transformation
temperatures and alloying elements in Cu–Al–Ni shape memory alloys.
Journal of Thermal Analysis and Calorimetry. 2013. 114(3): 1069-1074.
104. Chang, S. H. Influence of chemical composition on the damping
characteristics of Cu–Al–Ni shape memory alloys. Materials Chemistry and
Physics. 2011. 125(3): 358-363.
105. Recarte, V., Pérez-Landazábal, J. I., Nó, M. L. and San Juan, J. Study by
resonant ultrasound spectroscopy of the elastic constants of the β phase in
Cu-Al-Ni shape memory alloys. Materials Science and Engineering: A. 2004.
370(1-2): 488-491.
106. Recarte, V., Perez-Landazabal, J. I., Gomez-Polo, C., Sanchez-Alarcos, V.,
Cesari, E. and Pons, J. Vibrational and magnetic contributions to the entropy
change associated with the martensitic transformation of Ni-Fe-Ga
ferromagnetic shape memory alloys. J Phys Condens Matter. 2010. 22(41):
416001.
255
107. Miyazaki, S., Otsuka, K., Sakamoto, H. and Shimizu, K. The fracture of Cu–
Al–Ni shape memory alloy. Transactions of the Japan Institute of Metals.
1981. 22(4): 244-252.
108. Dutkiewicz, J., Czeppe, T. and Morgiel, J. Effect of titanium on structure and
martensic transformation in rapidly solidified Cu–Al–Ni–Mn–Ti alloys.
Materials Science and Engineering: A. 1999. 273: 703-707.
109. Van Humbeeck J, ChandrsekaranM and Stalmans R. Copper-based shape
memory alloys and the martensitic transformation. Proc. Int. Conf. Mart.
Trans. 1993. 25: 1015.
110. Chen, C. and Liu, T. Phase transformations in a Cu-14.2 Al-7.8 Ni alloy.
Metallurgical and Materials Transactions A. 2003. 34(3): 503-509.
111. Chentouf, S. M., Bouabdallah, M., Gachon, J. C., Patoor, E. and Sari, A.
Microstructural and thermodynamic study of hypoeutectoidal Cu–Al–Ni
shape memory alloys. Journal of Alloys and Compounds. 2009. 470(1-2):
507-514.
112. Ratchev, P., J. Van Humbeeck, L. Delaey On the formation of 2H stacking
sequence in 18R martensite plates in a precipitate containing CuAlNiTiMn
alloy Acta Metallurgica Et Materialia. 1993. 41(8): 2441-2449.
113. V. Recarte, I. H., J. Herreros, M.L. Nó, J.San Juan Precipitation of the stable
phases in Cu-Al-Ni shape memory alloys. Scripta Materialia. 1996. 34: 255-
260.
114. Font, J., Muntasell, J., Pons, J. and Cesari, E. Thermal cycling effects in high
temperature Cu-Al-Ni-Mn-B shape memory alloys. Journal of materials
research. 1997. 12(9): 2288-2297.
115. Morris, M. A. Microstructural Influence on Ductility and Shape Memory
Effect of some Modified Cu.Ni.Ai Alloys. Scripta Metallugica. 1991. 25:
1409-1414.
116. Lojen, G., Anžel, I., Kneissl, A., Križman, A., Unterweger, E., Kosec, B. and
Bizjak, M. Microstructure of rapidly solidified Cu–Al–Ni shape memory
alloy ribbons. Journal of Materials Processing Technology. 2005. 162–
163(0): 220-229.
117. M. Fremond, S. M. Shape Memory Alloys, Wien, New York: Springer-
Verlag. 1996.
118. K. Otsuka, C. M. W. Shape Memory Materials. Cambridge University Press,
256
Cambridge. 1998.
119. S. Miyazaki, K. O., H. Sakamoto, K. Shimizu. Study of Fracture in Cu-
Al-Ni Shape Memory Bicrystals. Trans. Jpn. Inst. Met. . 1981. 22 244-252.
120. S.W. Husain, P. C. C. Grain boundary embrittlement in Cu-AI-Ni β phase
alloys. J. Mater. Sci. . 1987. 22 2351-2356.
121. Lee, J. S. and Wayman, C. M. Grain refinement of Cu-Zn-Al shape memory
alloys. Metallography. 1986. 19(4): 401-419.
122. G.N. Sure, L. C. B. The mechanical properties of grain refined β- Cu-Al-Ni
strain- Memory alloys. Metall. Trans. A 1984. 15 1613-1621.
123. Bhattacharya, S., Bhuniya, A. and Banerjee, M. K. Influence of minor
additions on characteristics of Cu-Al-Ni alloy. Materials Science and
Technology. 1993. 9(8): 654-658.
124. Adachi, K., Hamada, Y. and Tagawa, Y. Crystal structure of the X-phase in
grain-refined Cu-Al-Ni-Ti shape memory alloys. Scripta Metallurgica. 1987.
21(4): 453-458.
125. Kim, J., Roh, D., Lee, E. and Kim, Y. Effects on microstructure and tensile
properties of a zirconium addition to a Cu-Al-Ni shape memory alloy.
Metallurgical and Materials Transactions A. 1990. 21(2): 741-744.
126. Morris, M. A. and Lipe, T. Microstructural influence of Mn additions on
thermoelastic and pseudoelastic properties of Cu-Al-Ni alloys. Acta
Metallurgica et Materialia. 1994. 42(5): 1583-1594.
127. Gao, Y., Zhu, M. and Lai, J. K. L. Microstructure characterization and effect
of thermal cycling and ageing on vanadium-doped Cu–Al–Ni–Mn high-
temperature shape memory alloy. Journal of Materials Science. 1998. 33(14):
3579-3584.
128. Adachi, K., Shoji, K. and Hamada, Y. Formation of (X) Phases and Origin of
Grain Refinement Effect in Cu-Al-Ni Shape Memory Alloys Added with
Titamium. ISIJ International. 1989. 29(5): 378-387.
129. Vajpai, S. K., Dube, R. K. and Sangal, S. Microstructure and properties of
Cu-Al-Ni shape memory alloy strips prepared via hot densification rolling of
argon atomized powder preforms. Materials Science and Engineering A.
2011. 529(1): 378-387.
130. Zhu, M., Ye, X., Li, C., Song, G. and Zhai, Q. ChemInform Abstract:
Preparation of Single Crystal CuAlNiBe SMA and Its Performances.
257
ChemInform. 2009. 40(34): no-no.
131. Morris, M. A. and S. Gunter. Effect of heat treatment and thermal cycling on
transformation temperatures of ductile Cu-Al-Ni-Mn-B alloys. Scripta
Metallurgica et Materiala. 1992. 26(11): 1663-1668.
132. D. W. Roh, J.W.K., T.J.Cho, Y. G. Kim Tensile properties and
microstructure of microalloyed Cu-A1-Ni-X shape memory alloys. Materials
Science and Engineering: A. 1991. 136: 17-23.
133. Khan, A. and Delaey, L. The Effect of Grain Size on the Strength of Cu-Al
Beta'-Martensite. Z Metallkd. 1969. 60(12): 949-951.
134. Xu, H., Zhu, M., Song, G., Mao, X. And Li, C. A. Study on Shape Memory
Performance of Single Crystal Cu-Al-Ni-Be Alloy [J]. Materials Review.
2008. 4: 036.
135. Xu, H. P., Song, G. F. and Mao, X. M. Influence of Be and Ni to Cu-Al Alloy
Shape Memory Performance. Advanced Materials Research. 2011. 197:
1258-1262.
136. Gomes, R. M., Veloso, A. C. R., Buono, V. T. L., Lima, S. J. G. and Melo, T.
A. A. Pseudoelasticity of Cu-13.8Al-Ni Alloys Containing V and Nb.
Advances in Science and Technology. 2008. 59: 101-107.
137. Zhu, M., Ye, X., Li, C., Song, G. and Zhai, Q. Preparation of single crystal
CuAlNiBe SMA and its performances. Journal of Alloys and Compounds.
2009. 478(1): 404-410.
138. F. Dagdelen, T. G., A. Aydogdu, Y. Aydogdu, O. Adigu zel Effects of
thermal treatments on transformation behaviour in shape memory Cu–Al–Ni
alloys. Materials Letters. 2003. 57: 1079-1085.
139. Van Humbeeck, J., Van Hulle, D. and Delacey, L. A Two-Stage Martensite
Transformation in a Cu-13. 99 mass% Al-3. 5 mass% Ni Alloy. Trans. Jpn.
Inst. Met. 1987. 28(5): 383-391.
140. Picornell, C., Pons, J. and Cesari, E. Effects of Thermal Ageing in, B-Phase
in Cu-Al-Ni Single Crystals. Journal de Physique-Colloques. 1997. 7(5): 323-
328.
141. Gastien, R., Corbellani, C., Sade, M. and Lovey, F. Thermal and
pseudoelastic cycling in Cu–14.1 Al–4.2 Ni (wt%) single crystals. Acta
materialia. 2005. 53(6): 1685-1691.
142. Wang, Z., Liu, X. F. and Xie, J. X. Effect of γ2 phase evolution on
258
mechanical properties of continuous columnar-grained Cu–Al–Ni alloy.
Materials Science and Engineering: A. 2012. 532: 536-542.
143. Suresh, N. and Ramamurty, U. The effect of ageing on the damping
properties of Cu–Al–Ni shape memory alloys. Smart materials and structures.
2005. 14(5): N47.
144. Cheniti, H., Bouabdallah, M. and Patoor, E. High temperature decomposition
of the β1 phase in a Cu–Al–Ni shape memory alloy. Journal of Alloys and
Compounds. 2009. 476(1-2): 420-424.
145. Balo, Ş. N. and Sel, N. Effects of thermal aging on transformation
temperatures and some physical parameters of Cu–13.5wt.%Al–4wt.%Ni
shape memory alloy. Thermochimica Acta. 2012. 536: 1-5.
146. Wei, Z., Peng, H., Zou, W. and Yang, D. Aging effects in a Cu-12Al-5Ni-
2Mn-1Ti shape memory alloy. Metallurgical and Materials Transactions A.
1997. 28(4): 955-967.
147. Singh, J. C., H.; Wayman, C.M. Transformation Sequence in a Cu-Al-Ni
Shape Memory Alloy at Elevated Temperatures. Metallurgical transactions.
A. 1986. 17 A(1): 65-72.
148. Singh, J. C., H.; Wayman, C.M Precipitation behavior of a CuAlNi shape
memory alloy at elevated temperatures" Scripta Metallurgica. 1985. 19(2):
231-234.
149. P. Rodriguez and G. Guenin. Thermal Aging Behaviour and Origin of a Cu-
Al-Ni Shape Memory Alloy. Materials Science and Engineering A. 1990.
129: 273-277.
150. Kuwano, N. and C. M. Wayman. Some Effects of Parent Phase Aging on the
Martensitic Transformation in A Cu-Al-Ni Shape Memory Alloy.
Metallurgical transactions. A, Physical Metallurgy and Materials Science.
1984. 15 A(4): 621-626.
151. Zárubová, N., Gemperlová, J., Gärtnerová, V. and Gemperle, A. Stress-
induced martensitic transformations in a Cu–Al–Ni shape memory alloy
studied by in situ transmission electron microscopy. Materials Science and
Engineering: A. 2008. 481-482: 457-461.
152. Zarubova, N., Gemperle, A. and Novak, V. Initial stages of γ2 precipitation in
an aged Cu-Al-Ni shape memory alloy. Materials Science and Engineering:
A. 1997. 222(2): 166-174.
259
153. Sakamoto, H., Sugimoto, K., Nakamura, Y., Tanaka, A. and Shimizu, K. i.
Martensite phase causing two way shape memory effect in Cu-13. 7 Al-4. 0
Ni(mass%) alloy single crystals. Mater. Trans., JIM(Japan). 1991. 32(2): 128-
134.
154. Sari, U., Kirindi, T., Ozcan, F. and Dikici, M Effects of aging on the
microstructure of a Cu-Al-Ni-Mn shape memory alloy. International Journal
of Minerals Metallurgy and Materials,. 2011. 18(4): 430-436.
155. Zarubova, N., Gemperle, A. and Novak, V. Ageing Phenornena in a Cu-Al-
Ni Alloy. Le Journal de Physique IV. 1997. 7(C5): C5-281-C285-286.
156. Morawiec, H. and Gigla, M. Effect of ageing on shape recovery in CuAlNi
alloy with Ti + B additions. Acta Metallurgica et Materialia. 1994. 42(8):
2683-2686.
157. N. F. Kennon and D. P. Dunne. Thermal Aging Behaviour and Origin of a
Cu-Al-Ni Shape Memory Alloy. Materials Science and Engineering: A. 1990.
129: 273-277.
158. Daricek, T., Lasek, J., Zarubova, N., Novak, V. and Bartuska, P. Composites
and Cu based shape memory alloys-Ageing effects in a Cu-Al-Ni shape
memory alloy. Journal de Physique-Colloques. 2001. 11(8): 179-184.
159. C. Picornell, J. Pons, E. Cesari. Cesari Mechanical stabilisation and
anomalous behaviour of the stress–strain loops in Cu–Al–Ni single crystals.
Scripta Materialia. 2006. 54: 459-463.
160. Picornell, C., Pons, J. and Cesari, E. Stress–temperature relationship in Cu–
Al–Ni single crystals in compression mode. Materials Science and
Engineering: A. 2004. 378(1): 222-226.
161. Aydogdu, A., Aydogdu, Y., Adigüzel, O. The influence of aging pn the
martensite ordering and stabilization in shape memory Cu-Al-Ni alloys.
Materials research bultetin 1997. 32: 507-513.
162. Aydogdu, A., Aydogdu, Y., Adigüzel, O. Improvement of Hardness and
Microstructures by Ageing in Shape Memory CuAlNi Alloys. Le Journal de
Physique IV. 1997. 07(C5): C5-311-C315-316.
163. Aksu Canbay, C. and Aydoğdu, A. Thermal analysis of Cu-14.82 wt% Al-
0.4 wt% Be shape memory alloy. Journal of Thermal Analysis and
Calorimetry. 2013. 113(2): 731-737.
260
164. Hondros, E. and Seah, M. Segregation to interfaces. International Metals
Reviews. 1977. 22(1): 262-301.
165. Stein, D., Johnson, W., White, C., Chadwick, G. and Smith, D. Grain
Boundary Structure and Properties. Academic Press, New York. 1976.
166.
Ni shape memory alloys. Scripta metallurgica et materialia. 1991. 25(4): 883-
888.
167. Leu, S., Chen, Y. and Jean, R. Effect of rapid solidification on mechanical
properties of Cu-Al-Ni shape memory alloys. Journal of materials science.
1992. 27(10): 2792-2798.
168. Hodgson, D., Wu, MH, Biermann, RJ Metals Handbook. ASM International,
Ohio. 1990. 2: 897.
169. Gall, K., Yakacki, C. M., Liu, Y., Shandas, R., Willett, N. and Anseth, K. S.
Thermomechanics of the shape memory effect in polymers for biomedical
applications. Journal of Biomedical Materials Research Part A. 2005. 73(3):
339-348.
170. Stöckel, D. The shape memory effect: phenomenon, alloys, applications. 报
告 (2000 年), NDC, Nitinol Devices & Components 公司, 美国加利福尼亚
州 Fremont, www. nitinol-europe. com/pdfs/smemory. pdf (2007 年 12 月 24
日浏览). 2000.
171. Leo, D. J., Weddle, C., Naganathan, G. and Buckley, S. J. Vehicular
applications of smart material systems. Proceedings of the 5th Annual
International Symposium on Smart Structures and Materials: International
Society for Optics and Photonics. 106-116.
172. Stoeckel, D. Shape memory actuators for automotive applications. Materials
& Design. 1990. 11(6): 302-307.
173. Wilkes, K. E. and Liaw, P. K. The fatigue behavior of shape-memory alloys.
JOM. 2000. 52(10): 45-51.
174. Hornbogen, E. Review Thermo-mechanical fatigue of shape memory alloys.
Journal of materials science. 2004. 39(2): 385-399.
175. Widdle, R. D., Grimshaw, M. T., Crosson-Elturan, K. S., Mabe, J. H.,
Calkins, F. T., Gravatt, L. M. and Shome, M. High stiffness shape memory
alloy actuated aerostructure. Google Patents. 2013.
261
176. Mani, R., Lagoudas, D. C. and Rediniotis, O. K. MEMS-based active skin for
turbulent drag reduction. Proceedings of the Smart Structures and Materials:
International Society for Optics and Photonics. 9-20.
177. Tawfik, M., Ro, J.-J. and Mei, C. Thermal post-buckling and aeroelastic
behaviour of shape memory alloy reinforced plates. Smart Materials and
Structures. 2002. 11(2): 297.
178. Furuya, Y. and Shimada, H. Shape memory actuators for robotic applications.
Materials & Design. 1991. 12(1): 21-28.
179. Wu, M. H. and Schetky, L. Industrial applications for shape memory alloys.
Proceedings of the Proceedings of the International Conference on Shape
Memory and Superelastic Technologies, Pacific Grove, California.
180. Russell, S. M. SMST-2000: Proceedings of the International Conference on
Shape Memory and Superelastic Technologies: SMST, the International
Organization on Shape Memory and Superelastic Technology. 2001.
181. Sari, U. Influences of 2.5wt% Mn addition on the microstructure and
mechanical properties of Cu-Al-Ni shape memory alloys. International
Journal of Minerals, Metallurgy, and Materials. 2010. 17(2): 192-198.
182. Tarhan, E. F. Aging Characteristics of Copper based Shape Memory Alloys.
Middle East Technical University; 2004.
183. Imran Khan, M., Kim, H. Y., Nam, T.-h. and Miyazaki, S. Formation of
nanoscaled precipitates and their effects on the high-temperature shape-
memory characteristics of a Ti50Ni15Pd5Cu10 alloy. Acta Materialia. 2012.
60(16): 5900-5913.
184. Kumar, M. and Gupta, R. Introduction to Shape Memory Alloys: Springer.
2008.
185. Bergeon, N., Guenin, G. and Esnouf, C. Study of the Faults Stackings in the
γ(f.c.c.)-ε(h.c.p.) Martensitic Transformation. J. Phys. IV France. 1997.
07(C5): C5-125-C125-130.
186. Putaux, J. L. and Chevalier, J. P. HREM study of self-accommodated thermal
ε-martensite in an FeMnSiCrNi shape memory alloy. Acta Materialia. 1996.
44(4): 1701-1716.
187. Eskil, M. and Kayali, N. X-ray analysis of some shape memory CuZnAl
alloys due to the cooling rate effect. Materials Letters. 2006. 60(5): 630-634.
188. Yildirim Aydogdu, A. A., Osman Adiguzel Self-accommodating martensite
262
plate variants in shape memory CuAlNi alloys. Journal of Materials
Processing Technology. 2002. 123: 498-500.
189. Friend, C. M. The effect of aluminium content on the martensite phase
stabilities in metastable CuAlNi alloys. Scripta Metallurgica. 1989. 23(10):
1817-1820.
190. M. Miki, Y. O., Y. Hiramatsu effects of B and Cr additions on the grain
refinement and ductility of a Cu-14Al-3Ni shape memory alloy. Nippon
Kinzoku Gakkai-si. 1987. 51(9): 815-823.
191. M. O. Lai, L. Lu, W. H. Lee. Influence of heat treatment on properties of
copper-based shape-memory alloy. Journal of Materials Science. 1996. 31:
1537-1543.
192. Fernández, J., Benedetti, A. V., Guilemany, J. M. and Zhang, X. M. Thermal
stability of the martensitic transformation of Cu–Al–Ni–Mn–Ti. Materials
Science and Engineering: A. 2006. 438-440: 723-725.
193. Sutou, Y., Omori, T., Koeda, N., Kainuma, R. and Ishida, K. Effects of grain
size and texture on damping properties of Cu–Al–Mn-based shape memory
alloys. Materials Science and Engineering: A. 2006. 438-440: 743-746.
194. Mallik, U. S. and Sampath, V. Influence of aluminum and manganese
concentration on the shape memory characteristics of Cu–Al–Mn shape
memory alloys. Journal of Alloys and Compounds. 2008. 459(1-2): 142-147.
195. Q. Xuan, J. B., T.Y. Hsu The effect of martensite ordering on shape memory
effect in a copper–zinc–aluminium alloy. Mater. Sci. Eng. 1987. 93: 205-211.
196. Salzbrenner, R. J. a. C., M. On the thermodynamics of thermoelastic
martensitic transformations. Acta Metallurgica. 1979. 27(5): 739-748.
197. Adigüzel, O. Martensite ordering and stabilization in copper based shape
memory alloys. Materials research bulletin. 1995. 30(6): 755-760.
198. Aydogdu, A., Aydogdu, Y. and Adiguzel, O. Long-term ageing behaviour of
martensite in shape memory Cu–Al–Ni alloys. Journal of materials
processing technology. 2004. 153: 164-169.
199. Zhang, X., Brinson, L. and Sun, Q.-P. The variant selection criteria in single-
crystal CuAlNi shape memory alloys. Smart materials and structures. 2000.
9(5): 571.
200. Tatar, C. Gamma irradiation-induced evolution of the transformation
temperatures and thermodynamic parameters in a CuZnAl shape memory
263
alloy. Thermochim. Acta. 2005. 437: 121-125.
201. Ortín, J. and Planes, A.. Thermodynamics of thermoelastic martensitic
transformations. Acta Metallurgica. 1989. 37(5): 1433-1441.
202. Huang, W. M., Wu, J. A., Lim, B. Y. And Vahhi, I. Behaviour of Young‟s
Modulus in Shape Memory Alloys upon Mechanical Loading. Mater Sci
ISSN. 2005: 1392-1320.
203. Motoyasu, G., Kaneko, M., Soda, H. and McLean, A. Continuously cast Cu-
Al-Ni shape memory wires with a unidirectional morphology. Metallurgical
and Materials Transactions A. 2001. 32(3): 585-593.
204. Lee, J. and Wayman, C. Grain refinement of a Cu-Al-Ni shape memory alloy
by Ti and Zr additions. Trans Jpn Inst Met. 1986. 27(8): 584-591.
205. Yang, N., Laird, C. and Pope, D. P. The cyclic stress-strain response of
polycrystalline, pseudoelastic Cu-14.5 wt pct Al-3 wt pct Ni alloy.
Metallurgical Transactions A. 1977. 8(6): 955-962.
206. Funakubo, H. Shape Memory Alloys: C R C Press LLC. 1987.
207. Shimizu, K. and Otsuka, K. Optical and electron microscope observations of
transformation and deformation characteristics in Cu-Al-Ni marmem alloys.
Shape Memory Effects in Alloys: Springer. 59-87; 1975.
208. Suezawa, M. and Sumino, K. Lattice distortion and the effective shear
modulus along a coherent twin boundary. physica status solidi (a). 1976.
36(1): 263-268.
209. Izadinia, M. and Dehghani, K. Structure and properties of nanostructured Cu-
13.2Al-5.1Ni shape memory alloy produced by melt spinning. Transactions
of Nonferrous Metals Society of China. 2011. 21(9): 2037-2043.
210. Bhattacharya, K. Microstructure of Martensite: Why it Forms and how it
Gives Rise to the Shape-memory Effect: OUP Oxford. 2003.
211. Churchill, C. B., Shaw, J. A. and Iadicola, M. A. Tips and tricks for
characterizing shape memory alloy wire: Part 3-localization and propagation
phenomena. Experimental Techniques. 2009. 33(5): 70-78.
212. I. Hurtado, P. R., J. Van Humbeeck and L. Delaey A fundamental study of
the X-phase preciptation in Cu-Al-Ni-Ti-(Mn) shape memory alloys. Acta
Materialia. 1995. 44: 3299-3306.
213. Lee, JS and Wayman, CM. Grain Refinement of a Cu–Al–Ni Shape Memory
264
Alloy by Ti and Zr Additions. Transactions of the Japan Institute of Metals. 1986.
27(8): 584-591.
214. Sure, G. N. B., L. C. The mechanical properties of grain refined β- cuaini
strain-memory alloys. Metallurgical Transactions A. 1984. 15(8): 1613-1621.
215. Malarría, J., Elgoyhen, C., Vermaut, P., Ochin, P. and Portier, R. Shape
memory properties of Cu-based thin tapes obtained by rapid solidification
methods. Materials Science and Engineering: A. 2006. 438-440: 763-767.
216. Dutkiewicz, J., Pons, J. and Cesari, E. Effect of γ precipitates on the
martensitic transformation in Cu-Al-Mn alloys. Materials Science and
Engineering: A. 1992. 158(1): 119-128.
217. Cullity, B. D. Elements of X-Ray Diffraction: Addison-Wesley Publishing
Company. 1978.
218. Yang, G.-S., Lee, J.-K. and Jang, W.-Y. Effect of grain refinement on phase
transformation behavior and mechanical properties of Cu-based alloy.
Transactions of Nonferrous Metals Society of China. 2009. 19(4): 979-983.
219. Aydogdu, A., Aydogdu, Y. and Adiguzel, O. Long-term ageing behaviour of
martensite in shape memory Cu–Al–Ni alloys. Journal of Materials
Processing Technology. 2004. 153-154: 164-169.
220. Saiji Matsuoka, M. H., Ryuichiro Oshima and Francisco Eiichi Fujita
Improvement of Ductility of Melt Spun Cu-Al-Ni Shape Memory Alloy
Ribbons by Addition of Ti or Zr
Japanese Journal of Applied Physics, Part 1: Regular Papers and Short Notes and
Review Papers. 1983. 22(Part 2, No. 8): 528-530.
221. Matsuoka, S., Hasebe, M., Oshima, R. and Fujita, F. E. Improvement of
ductility of melt spun Cu-Al-Ni shape memory alloy ribbons by addition of
Ti or Zr. Japanese Journal of Applied Physics. 1983. 22(8): L528-L530.
222. Yang, Q. P., Sun, L. and Feng, Y. Z. Experiment of Beam Crack Repair
Using Shape Memory Alloy. Applied Mechanics and Materials. 2011. 71-78:
1707-1710.
223. Gollerthan, S., Young, M., Baruj, A., Frenzel, J., Schmahl, W. and Eggeler,
G. Fracture mechanics and microstructure in NiTi shape memory alloys. Acta
Materialia. 2009. 57(4): 1015-1025.
224. Wycech, J. S. Influencing parameters on the fracture resistance of aluminum
alloys. Massachusetts Institute of Technology; 1971.
265
225. Sarı, U. and Aksoy, İ. Electron microscopy study of 2H and 18R martensites
in Cu–11.92wt% Al–3.78wt% Ni shape memory alloy. Journal of Alloys and
Compounds. 2006. 417(1-2): 138-142.
226. Morawiec, H., Ilczuk, J., Stróz, D., Goryczka, T. and Chrobak, D. Two-stage
martensitic transformation in NiTi alloys caused by stress fields. Le Journal
de Physique IV. 1997. 7(C5): C5-155-C155-159.
227. Yang, S., Liu, Y., Wang, C. and Liu, X. Martensite stabilization and thermal
cycling stability of two-phase NiMnGa-based high-temperature shape
memory alloys. Acta Materialia. 2012. 60(10): 4255-4267.
228. Font, J., Cesari, E., Muntasell, J. and Pons, J. Thermomechanical cycling in
Cu–Al–Ni-based melt-spun shape-memory ribbons. Materials Science and
Engineering: A. 2003. 354(1-2): 207-211.
229. Picornell, C., Pons, J. and Cesari, E. Effects of thermal ageing in β-phase in
Cu-Al-Ni single crystals. Le Journal de Physique IV. 1997. 7(C5): C5-323-
C325-328.
230. Daricek, T., Lasek, J., Zarubova, N., Novak, V. and Bartuska, P. Ageing
effects in a Cu-Al-Ni shape memory alloy. Le Journal de Physique IV. 2001.
11(PR8): Pr8-179-Pr178-184.
231. Tarhan, E. F. Aging Characteristics of Copper based Shape Memory Alloys.
Middle East Technical University; 2004.
232. Roh*, D. W., Kim, J. W., Cho, T. J. and Kim, Y. G. Tensile properties and
microstructure of microalloyed Cu-A1-Ni-X shape memory alloys. Materials
Science and Engineering: A. 1991. 136: 17-23.
233. Leslie, W. C. The physical metallurgy of steels: Hempisphere Pub. Corp.
1981.
234. Kennon, N. F., Dunne, D. P. and Middleton, L. Aging Effects in Copper-
Based Shape Memory Alloys. Metallurgical Transactions A. 1982. 13(4):
551-555.
235. Dogan, E. CoNiGa High Temperature Shape Memory Alloys. Texas A&M
University; 2010.
236. Otsuka, K. and Ren, X. Recent developments in the research of shape
memory alloys. Intermetallics. 1999. 7(5): 511-528.
237. Ma, Y., Yang, S., Wang, C. and Liu, X. Tensile characteristics and shape
memory effect of Ni56Mn21Co4Ga19 high-temperature shape memory alloy.
266
Scripta Materialia. 2008. 58(10): 918-921.
238. Yang, J. P. and Kim, Y. G. Tensile properties and shape memory effect of
chromium-varied Fe-30Mn-5Si-Cr shape memory alloys. Materials Science
and Engineering: A. 1992. 154(1): L1-L3.
239. Duerig, T. and Pelton, A. Ti-Ni shape memory alloys. Materials properties
handbook: Titanium alloys. 1994: 1035-1048.
240. Ma, Y., Yang, S., Liu, Y. and Liu, X. The ductility and shape-memory
properties of Ni–Mn–Co–Ga high-temperature shape-memory alloys. Acta
Materialia. 2009. 57(11): 3232-3241.
241. Gao, Y., Zhu, M. and Lai, J. Microstructure characterization and effect of
thermal cycling and ageing on vanadium-doped Cu–Al–Ni–Mn high-
temperature shape memory alloy. Journal of materials science. 1998. 33(14):
3579-3584.
242. Lin, B., Gall, K., Maier, H. J. and Waldron, R. Structure and
thermomechanical behavior of NiTiPt shape memory alloy wires. Acta
biomaterialia. 2009. 5(1): 257-267.
243. Wu, S., Lin, H. and Chen, S. Phenomenological analysis of martensitic
transformation in cold-rolled TiNi-base shape memory alloys. Materials
chemistry and physics. 2001. 68(1): 149-156.