Radom, 29 maja 2008

TRIBOCHEMIATRIBOCHEMIA - warsztaty - warsztaty tribologicznetribologiczne

INSTYTUT TECHNOLOGII EKSPLOATACJI INSTYTUT TECHNOLOGII EKSPLOATACJI - PAŃSTWOWY INSTYTUT BADAWCZY- PAŃSTWOWY INSTYTUT BADAWCZY

Monika MAKOWSKA

Marian GRĄDKOWSKI

Institute for Sustainable Technologies

- National Research InstitutePulaskiego 6/10

26-600 Radom

TRANSFORMATIONSTRANSFORMATIONS

OF HYDROCARBONS UNDER OF HYDROCARBONS UNDER

MIXED FRICTION CONDITIONSMIXED FRICTION CONDITIONS

lubricant

Background of the study

Dry frictionDry frictionMixed frictionMixed frictionBoundary frictionBoundary friction

Boundary layers

Experimental procedure

2. Hydraulic oil HL-46

1. n-Hexadecane – model lubricant

CC1616HH3434

LubricantsLubricants

CH3

CH2

CH2

CH2

CH2

CH2

CH2

CH2

CH2

CH2

CH2

CH2

CH2

CH2

CH2

CH3

Experimental procedure

T-11 ball-on-disk machine

pp

v

Ball

Disk-holding cup

Lubricant

DiskHeater

T-11 ball-on-disk machine which allows to run testsT-11 ball-on-disk machine which allows to run tests at elevated temperatures: at elevated temperatures:

material of the friction pair: bearing steel equivalent to AISI 52100,material of the friction pair: bearing steel equivalent to AISI 52100, ball: ball: 6,35 mm6,35 mm ( (1/4”)1/4”), R, Raa = 0,3 = 0,3 m, 58-63 HRC,m, 58-63 HRC,

disk: disk: 25,4 mm25,4 mm ( (1”)1”), R, Raa = 0,25 = 0,25 m, 58-63 HRC.m, 58-63 HRC.

Rubbing tests conditions (mixed friction):Rubbing tests conditions (mixed friction): radius of radius of ball movement on the disk surfaceball movement on the disk surface: ~10 mm,: ~10 mm, load: 9,81 or 49,05 N,load: 9,81 or 49,05 N, sliding velocity: 0,25 m/s,sliding velocity: 0,25 m/s, sliding distance: 500 m, 3000 m, 18000 m,sliding distance: 500 m, 3000 m, 18000 m, temperature: 20temperature: 20170±5°C.170±5°C.

Tribological tests conditionsTribological tests conditions

p

v

13 5

4

2

Experimental procedure

SEM/EDSSEM/EDSScanning Electron Microscopy

Energy Dispersion SpectroscopyIdentification of the elements in external layer of rubbing surface

Investigation of the wear scar surfaceInvestigation of the wear scar surface

FTIRMFTIRMFourier Transform Infrared

MicrospectrophotometryIdentification of the organic productson a rubbing surface

XPSXPSX-Ray Photoelectron

SpectroscopyIdentification of the chemical bonds types in external layer of rubbing surface

Secondary Ion Mass Spectrometry

Determination of the molecular weight of products present on the rubbing surface

SIMSSIMS

R2 = 0,8746

R2 = 0,8968

0,55

0,65

0,75

0,85

0,95

1,05

1,15

1,25

1,35

0 20 40 60 80 100 120 140 160 180

Temperature, [oC]

Wea

r sc

ar d

iam

eter

, [m

m];

Fri

ctio

n fo

rce,

[N

] Friction force and wear scar diameter – CFriction force and wear scar diameter – C16HH34

Tribological tests results

Dependence of the friction force and wear scar diameteron the temperature of friction pair lubricated with C16H34

(load of 10 N, sliding distance of 500 m)

80-90°C

Dependence of the wear scar diameter on the temperature of friction pair (load of 10 or 50 N, friction distance of 3000 or 18000 m)

Wear scar diameter – HL-46Wear scar diameter – HL-46

Tribological tests results

R2 = 0,9849

R2 = 1

0,2

0,3

0,4

0,5

0,6

0,7

0,8

0,9

10 30 50 70 90 110 130

Temperature, [0C]

Wea

r sca

r dia

met

er, [

mm

] load = 50 N, s = 18 000 m

load = 10 N, s = 3 000 m

Profilograms of the disk surfaces after rubbing at different temperatures (load of 10 N, sliding distance of 3000 m)

ProfilogramsProfilograms –– CC16HH34

Rubbing surface analysis

Rubbing surface analysis

SEM images of the wear scar formed at different temperatures

20oC 100oC 170oC

SEM imagesSEM images –– CC16HH34

Rubbing surface analysis

Products layered on the steel surface at 100C (sliding distance of 3000 m)

SEM imagesSEM images –– CC16HH34

Relative content of carbon, iron and oxygen on the disk rubbing surface (load of 10 N, distance of 3000 m) along the marked lines: at 100°C (H-100) and 170°C (H-170)

(a and b mark the inner and the outer boundary of the friction track)

Rubbing surface analysis

SEM/EDS analysisSEM/EDS analysis –– CC16HH34

NoContent [% (m/m)]

Iron Carbon Oxygen Oxygen/carbon

1 90,82±2,38 7,15±1,50 0,00 -

2 86,24±2,23 11,80±1,39 0,00 -

3 30,52±1,07 62,05±1,40 6,98±1,14 0,11

4 98,45±2,53 0,00 0,00 -

5 88,59±2,32 8,94±1,64 0,24±1,18 0,03

6 42,74±1,31 50,99±1,64 5,10±0,55 0,10

7 22,88±0,96 68,72±1,35 7,47±1,11 0,11

8 84,25±2,20 13,75±1,56 0,48±1,20 0,035

9 70,34±1,86 27,72±2,13 0,68±1,34 0,025

10 69,86±1,83 27,37±1,31 1,04±1,07 0,038

11 16,11±0,84 75,68±1,32 7,77±1,32 0,10

12 6,59±0,34 76,58±0,82 16,32±0,88 0,21

13 8,40±0,47 80,50±0,97 10,52±0,45 0,13

Rubbing surface analysis

Elemental composition of the products layered on the steel surface at 100oC (blue cells contain data concerning points within the wear scar)

Presence of the elements on rubbing surface – SEM/EDSPresence of the elements on rubbing surface – SEM/EDS

IR spectra of the IR spectra of the tribotribochemichal products layered on the steel surface after chemichal products layered on the steel surface after static and rubbing testsstatic and rubbing tests

4000,0 3000 2000 1500 1000 700,0

0,0

10

20

30

40

50

60

70

80

90

100,0

cm-1

%T

2958,92

2934,522856,25

1467,10

1378,10

721,45

4000,0 3000 2000 1500 1000 700,0

0,0

10

20

30

40

50

60

70

80

90

100,0

cm-1

%T

2958,92

2934,522856,25

1467,10

1378,10

721,45

3993,0 3000 2000 1500 1000 707,0

-10,0

0

10

20

30

40

50

60

70

80

90

100

110

120,0

cm-1

%T

3607,54

2939,882861,47

2731,792674,73

2024,68

1468,85

1378,17

1303,31

1132,34

1077,71 890,97

722,08

3993,0 3000 2000 1500 1000 707,0

-10,0

0

10

20

30

40

50

60

70

80

90

100

110

120,0

cm-1

%T

3607,54

2939,882861,47

2731,792674,73

2024,68

1468,85

1378,17

1303,31

1132,34

1077,71 890,97

722,08

4000,0 3000 2000 1500 1000 600,0

0,0

10

20

30

40

50

60

70

80,0

cm-1

%T

3509,12

2925,232855,82

1730,97

1594,89

1460,311377,73

1252,631179,23

723,53

n-hexadecane after static test

after rubbing test

Investigation of the boundary layer structure

IdentificationIdentification ofof thethe organicorganic products on rubbing surfaceproducts on rubbing surface - - FTIRMFTIRM

4000,03000200015001000600,0

0,0

10

20

30

40

50

60

70

80,0

cm-1

%T

3509,12

2925,232855,82

1730,97

1594,89

1460,311377,73

1252,631179,23

723,53

Analysis of the IR spectrum of Analysis of the IR spectrum of tribochemicaltribochemical products layered products layeredon the steel rubbing surfaceon the steel rubbing surface

—C=O,>C=C<, —COO—, [R(COO)m]nMe

C—H,

—OH

=C—H—OH, —COOH, (RCOO)nMe C—O

Investigation of the boundary layer structure

IdentificationIdentification ofof thethe organicorganic products on rubbing surfaceproducts on rubbing surface - - FTIRMFTIRM

Investigation of the boundary layer structure

ESCA/XPS survey profile of the steel disk lubricated by n-ESCA/XPS survey profile of the steel disk lubricated by n-

hexadecane during rubbing testhexadecane during rubbing test

708 532 284

Fe2p

O1s C1s

Identification of the chemical bond type - XPSIdentification of the chemical bond type - XPS

Investigation of the boundary layer structure

Analysis of ESCA/XPS spectrum of Analysis of ESCA/XPS spectrum of tribotribochemichal productschemichal products

708 532 284

Fe2p

O1s C1s

6000

5000

3000

2000

1000

0

4000

c/s

740 730 720 710 700Binding energy [eV ]

1

2

0,5

1,5

0

c/s

545 540 535 530 525Binding energy [eV ]

10000

15000

5000

0

c/s

300 295 290 285 280Binding energy [eV ]

Fe2p

O1s

C1s

Fe2p

O1s C1s

Identification of the chemical bond type - XPSIdentification of the chemical bond type - XPS

Investigation of the boundary layer structure

Result of the overlapping peak separation in O1s photoelectron spectrumResult of the overlapping peak separation in O1s photoelectron spectrum

708 532 284

Fe2p

O1s C1s

6000

5000

3000

2000

1000

0

4000

c/s

740 730 720 710 700Binding energy [eV ]

1

2

0,5

1,5

0

c/s

545 540 535 530 525Binding energy [eV ]

10000

15000

5000

0

c/s

300 295 290 285 280Binding energy [eV ]

Fe2p

O1s

C1s

Fe2p

O1s C1s

Identification of the chemical bond type - XPSIdentification of the chemical bond type - XPS

0

1

2

3

4

5

6

7

8

9

10

544 542 540 538 536 534 532 528 526530

536,18 533,68

531,61

529,81

Binding Energy [eV ]

N(E

)/E

Fe2O3

C=O (org.)

C–O (org.)

O1s bond - 532 eV

Chemical structure of the products layered on the rubbing surfaceChemical structure of the products layered on the rubbing surface

R = ~3-12 carbon atoms (C3-12)

Investigation of the boundary layer structure

Identification of the Identification of the tribotribochemical products structurechemical products structure

–R–

HHCCHH

HH

284,

5828

4 ,58

CCHH

286,

4028

6 ,40

HH

Fe

711,

5071

1,50

CO

288,

2828

8,28

O

536

536 ,,

1818

531531,,6161

Conclusions

ConclusionsConclusions

Aliphatic saturated hydrocarbons Aliphatic saturated hydrocarbons undergo conversionsundergo conversions underunder the mixed friction conditions the mixed friction conditions

These products are organic salts of carboxylic acids These products are organic salts of carboxylic acids and ironand iron

They influence the friction conditions and may They influence the friction conditions and may decrease the weardecrease the wear

These phenomena may be applied in lubrication These phenomena may be applied in lubrication processes, e.g. processes, e.g. iin developing ecological lubrication n developing ecological lubrication techniquestechniques

Thank You for Your Thank You for Your attentionattention