bab 1 what are materials1

8/15/2019 Bab 1 What Are Materials1

http://slidepdf.com/reader/full/bab-1-what-are-materials1 1/53

What are Materials?

• That’s easy! Look around.• Our clothes are made of materials,

our homes are made of materials -mostly manufactured. Glasswindows, inyl sidin, metalsilerware, ceramic dishes"

• Most thins are made from manydi#erent kinds of materials.



What are Materials?• Materials may be defned as substance

o which something is composed ormade.

• We obtain materials rom earth crust andatmosphere.

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• Examples Silicon and Iron

constitute 27.72 and 5.00percentage o weight oearths crust respectiely.

!itrogen and "#ygen constitute 7$.0$ and20.%5 percentage o dryair by olume

respectiely.



Materials $cience

• %e&ned as the study of the'ro'erties of solid materials and howthose 'ro'erties are determined (y amaterial’s com'osition and structure.



)ro'erties are the way the material res'onds to theenironment and e*ternal forces.

Mechanical 'ro'erties + res'onse to mechanical forces,strenth, etc.

&lectrical and magnetic 'ro'erties - res'onse electrical and

manetic &elds, conductiity, etc.'hermal 'ro'erties are related to transmission of heat andheat ca'acity.

"ptical 'ro'erties include to a(sor'tion, transmission and

scatterin of liht.(hemical stability in contact with the enironment - corrosionresistance.

)roperties



Models Materials

Why study materials?• a''lied scientists or enineers must make material choices• materials selection

– in-serice 'erformance – deterioration – economics

T"really, eeryone makes material choices!aluminum lass 'lastic



Materials $cience and/nineerin

• 0n interdisci'linary study that com(inesmetallury, 'hysics, chemistry, andenineerin to sole real-world 'ro(lems

with real-world materials in an acce'ta(lesocietal and economical manner.• The oal of materials science is to ena(le

the scientist and enineer to desin,select, and use materials for s'eci&ca''lications and to deelo' new materialsfor future a''lications.



MATERIALS SCIENCE & ENGINEERING

PHYSICAL MECHANICAL ELECTRO-

CHEMICAL

TECHNOLOGICAL

• Extractive• Casting• Metal Fr!ing• "el#ing• P$#er Metall%rg• Mac'ining

• Str%ct%re• P'sical

Pr(erties

$cience of Metallury

• )e*r!atin

+e'avi%r

• T'er!#na!ics• C'e!istr• Crrsin

T'e ,ra# scienti*ic an# tec'nlgical seg!ents * Materials Science are s'$n

in t'e #iagra! ,el$

T gain a c!(re'ensive %n#erstan#ing * !aterials science. all t'ese as(ects

'ave t ,e st%#ie#



1

• Subatomic leel

/lectronic structure of indiidual atomsthat de&nes interaction amon atoms

2interatomic (ondin3.

• *tomic leel

0rranement of atoms in materials 2for

the same atoms can hae di#erent'ro'erties, e.. two forms of car(on4ra'hite and diamond3

•

Microscopic structure0rranement of small rains of materialthat can (e identi&ed (y microsco'y.

•

Macroscopic structure$tructural elements that may (e iewed

Structure

Monarch butterfly~ 0.1 m

Annealing * a (l&cr&stalline grain str%ct%re

/) si!%latin %sing Mnte Carl Ptts !#el

/) si!%latins invlve 01.111 sites an# ta2es a #a& t r%n n a *ast

$r2statin. 3) si!%latins invlve 40 !illin sites. r%ns n 5111 (rcessrs * ASCI-Re#



5

+ength,scales

0nstrom 6 78 6 797:,:::,:::,::: meter 6 7:-7: m

;anometer 6 7: nm 6 797,:::,:::,::: meter 6 7:-5 m

Micrometer 6 7<m 6 797,:::,::: meter 6 7:-= m

Millimeter 6 7mm 6 797,::: meter 6 7:-> m

nteratomic distance @ a few 8

0 human hair is @ A: <m

/lonated (um's that make u' the data track on B% are@ :.A <m wide, minimum :.1> <m lon, and 7CA nm hih


http://slidepdf.com/reader/full/bab-1-what-are-materials1 10/53 The Materials Tetrahedron

A !aterials scientist 'as t cnsi#er *%r 6intert$ine#7 cnce(ts. $'ic' are sc'e!aticall s'$n as t'e

6Materials Tetra'e#rn7

"'en a certain (er*r!ance is ex(ecte# *r! a c!(nent t'e 6ex(ectatin7 is (%t *rt' as a set *

(r(erties T'e !aterial is snt'esi8e# an# *%rt'er !a#e int a c!(nent , a set * (rcessing !et'#s

9casting. *r!ing. $el#ing. ($#er !etall%rg etc:

T'e str%ct%re 9at vari%s lengt'scales: is #eter!ine# , t'is (rcessing

T'e str%ct%re in t%rn #eter!ines t'e (r(erties. $'ic' $ill #ictate t'e (er*r!ance * t'e

c!(nent

Hence eac' * t'ese as(ects is #e(en#ent n t'e t'ers

T'e Materials Tetra'e#rn

T'e ,ra# gal * Materials Science is t%n#erstan# an# 6engineer7 t'is tetra'e#rn

http://var/www/apps/conversion/tmp/scratch_4/Chapter_1b_Lengthscales.ppt

http://var/www/apps/conversion/tmp/scratch_4/Chapter_1b_Lengthscales.ppt



Models Materials

Materials $cience and/nineerin

structure

'ro'erties• material

characteristic• res'onse to e*ternal

stimulus• mechanical,

electrical, thermal,manetic, o'tical,deterioratie

'erformance• (ehaior in a

'articulara''lication

• arranement of internal com'onen• su(atomic• atomic• microsco'ic• macrosco'ic 2(ulk3

• method of're'arin

material

'rocessincharacteriDation



What do MS& students do

• They . . . .• Design and invent new materials foremerging applications

• Develop new processes for manufacturing

materials• Relate structure and properties to processing methods

• Work on teams to invent the future

• Develop their ideas from the nanoscale up!• They research, publish, travel, study abroad

• And so much more…

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Iistory of Materials

• Materials are so im'ortant in thedeelo'ment of ciiliDation

• /en our history has (een de&ned (y the

materials we use"• The stone ae• The (ronDe ae• The iron ae

• What would (e a ood material name fortoday?




• Man has (een studyin materials since (eforeleain the cae.

• %ue to lack of communication, early man s'enthundreds of millennia e*'erimentin with stonetools.

• einnin of the Material $cience - )eo'le (eanto make tools from stone + $tart of the $tone 0ea(out two million years ao.

• ;atural materials4 stone, wood, clay, skins, etc.• The &rst metal tools a''eared 'erha's only si*

thousand years ao.




• The $tone 0e ended a(out A::: years ao withintroduction of ronDe in the Jar /ast.

• ronDe is an alloy 2a metal made u' of more thanone element3, co''er K CA of tin K other

elements.• ronDe4 can (e hammered or cast into a ariety

of sha'es, can (e made harder (y alloyin, corrodeonly slowly after a surface o*ide &lm forms.

• t was found that the 'ro'erties of a material could(e altered (y heat treatments and (y the additionof other su(stances 2alloyin in case of metals3.




• The ron 0e (ean a(out >::: years ao andcontinues today.

• se of iron and steel, a stroner and chea'er materialchaned drastically daily life of a common 'erson.

• The ne*t (i ste' was the discoery of a chea''rocess to make steel around 71A:, which ena(ledthe railroads and the (uildin of the moderninfrastructure of the industrial world.

• 0s our knowlede of materials rows, so does theso'histication of our tools.• The more so'histicated our tools, the more

so'histicated our accom'lishments.



• 0e of 0danced materials4throuhout the ron 0e many newty'es of materials hae (een

introduced 2ceramic,semiconductors, 'olymers,com'osites"3.

• nderstandin of the relationshipamong structure/ properties/processing/ and perormance o

materials.



CC

0 (etter understandin of structure-com'osition-'ro'erties relations haslead to a remarka(le 'roress in 'ro'erties of materials. /*am'le is thedramatic 'roress in the strenth to density ratio of materials, that resultedin a wide ariety of new 'roducts, from dental materials to tennis racHuets.



The evolution of engineering materials with time ote the highly nonlinear scale"#rom $ # Ashby, Materials $election in Mechanical %esin, %nd ed, &utterworth'(einemann, )*ford, +-

WW

ncreasin demand ofnot only hih Huality

metallic alloys (ut non-metallic materials.



.chematic illustration of theintegral relationship amongmaterials, the processing ofthose materials, andengineering design

)rocessing and SelectingMaterials

Materials/ esign and)rocessing are stronglyinter,related.

-or the successulselection o materials/ onehas to understand therelationships among thesethree components.

/ l f M t i l



/*am'le of Materials/nineerin Work + Ii'

m'lant

• With age or certain illnesses 1ointsdeteriorate. )articularly those with large

loads such as hip3.

Adapted from Fig. 22.25, Callister 7e.



/*am'le + Ii' m'lant

• 4euirements – mechanical

strength manycycles3

– good lubricity

– biocompatibility

0da'ted from Ji. CC.CF, /allister0e



/*am'le + Ii' m'lant

0da'ted from Ji. CC.CF, /allister0e



$olution + Ii' m'lant

• Ney )ro(lems tooercome4 – f#ation agent to hold

acetabular cup – cup lubrication

material – emoral stem – f#ing

agent “glue”3

– must aoid any debris

in cup – Must hold up in body

chemistry – Must be strong yet

6e#ible

Acetabular

Cup and

Liner

all

Jemoral$tem



Blassi&cation of Materials

Metals and 0lloys Beramics, Glasses,and Glass-ceramics )olymers 2'lastics3, Thermo'lastics and Thermosets

$emiconductors Bom'osite Materials



The Mars oers - $'irit andO''ortunity

Spirit and "pportunity are made up o materials such as Metals (eramics (omposites )olymers Semiconductors

www.nasa.gov

T f M t i l



Ty'es of Materials• Metallic Materials

(omposed o one or moremetallic elements. Example:- Iron, Copper, Aluminum.

Metallic element may combinewith nonmetallic elements. Example:- Silicon Carbide, Iron xide.

Inorganic and hae crystalline structure.

8ood thermal and electricconductors.

Metals and *lloys

-errous &g9 Steel/(ast Iron

!onerrous&g9(opper*luminum

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/*am'les of ceramic materials ranin from household to hih'erformance com(ustion enines which utiliDe (oth metals andceramics.

(eramics

T f M t i l



Ty'es of Materials

• )olymeric )lastic3 Materials "rganic giant molecules and mostly

noncrystalline. Some are mi#tures o crystalline and

noncrystalline regions. )oor conductors o electricity and

hence used as insulators. Strength and ductility ary greatly. +ow densities and decomposition

temperatures.

Examples- !ol$ vin$l Chloride %!&C', !ol$ester#

Applications

- Appliances, (&(s, )abrics etc#

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)olymers include P)lasticsQ and ru((er materials

)olymers



Ty'es of Materials

• (omposite Materials Mi#ture o two or more materials. (onsists o a fller material and a binding material. Materials only bond/ will not dissole in each other. Mainly two types

o -ibrous9 -ibers in a matri#o )articulate9 )articles in a matri#

,Matri# can be metals/ ceramic or polymer Examples

-iber 8lass 4einorcing material in a polyesteror epo#y matri#3

(oncrete 8raels or steel rods reinorced incement and sand3

Applications

- *ircrat wings and engine/ construction.

1-8



)olymer com'osite materials4 reinforcin lass&(ers in a 'olymer matri*.

(omposites

Ty'es of Materials



Ty'es of Materials• /lectronic Materials

!ot Ma1or by olume but eryimportant.

Silicon is a common electronicmaterial.

Its electrical characteristics arechanged by adding impurities.

Examples- Silicon chips/ transistors

Applications- (omputers/ Integrated (ircuits/

Satellites etc.

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$i wafer for com'uter chi'deices.

Semiconductors

Micro-/lectrical-Mechanical

$ystems 2M/M$3



e'resentatie e*am'les,a''lications, and 'ro'erties for each

cateory of materials

/*am'le of 0''lications )ro'erties

Metals and 0lloys

Gray cast iron 0utomo(ile enine (locks Basta(le, machina(le,i(ration dam'in

Beramics andGlasses $iOC-;aCO-BaO Window lass O'tically trans'arent,

thermally insulatin)olymers )olyethylene Jood 'ackain /asily formed into thin,

Re*i(le, airtiht &lm



/*am'le of 0''lications )ro'erties

$emiconductors$ilicon Transistors and interated niHue electrical

circuits (ehaior

Bom'osites Bar(ide cuttin tools for Iih hardness, yet Tunsten car(ide machinin ood shock resistance

-co(alt 2WB-Bo3

Ta(le Bontinued



;/113+r2s<C

leP%,lis'ing<T'!snLearning=

4epresentatie strengths o arious categories o materials



* section through a 1et engine.'he orward compressionsection operates at low tomedium temperatures/ andtitanium parts are oten used.'he rear combustion sectionoperates at high temperaturesand nic<el,based superalloysare reuired. 'he outside shell

e#periences low temperatures/and aluminum and compositesare satisactory. (ourtesy o 8&*ircrat &ngines.3

* ariety o comple# ceramiccomponents/ including impellersand blades/ which allow turbine

engines to operate moree=ciently at highertemperatures. (ourtesy o(ertech/ Inc.3



)olymers are usedin a ariety o

electronic deices/including thesecomputer dipswitches/ wheremoisture resistanceand low

conductiity arereuired. (ourtesyo ('S (orporation.3

Integrated circuitsor computers and

other electronicdeices rely on theuniue electricalbehaior osemiconductingmaterials.

(ourtesy o 4ogers(orporation.3

'he >,wing oradanced helicopters

relies on a materialcomposed o acarbon,fber,reinorced polymer.(ourtesy o Si<ors<y*ircrat iision?

@nited 'echnologies(orporation.3



Blassi&cation of Materials-ased on $tructure

Brystalline material is a material com'rised of one ormany crystals. n each crystal, atoms or ions show alon-rane 'eriodic arranement.

Single crystal is a crystalline material that is madeof only one crystal 2there are no rain (oundaries3. Grains are the crystals in a 'olycrystalline material. )olycrystalline material is a material com'rised ofmany crystals 2as o''osed to a sinle-crystal materialthat has only one crystal3. Grain (oundaries are reions (etween rains of a'olycrystalline material.



- t t i l i



%esin of materials hain s'eci&c desired characteristics directly from ourknowlede of atomic structure.

• MiniaturiBation9 P;anostructuredS materials, with microstructure thathas lenth scales (etween 7 and 7:: nanometers with unusual 'ro'erties.

/lectronic com'onents, materials for Huantum com'utin.

• Smart materials9 air'lane wins that deice themseles, (uildins thatsta(iliDe themseles in earthHuakes"

• &nironment,riendly materials9 (ioderada(le or 'hotoderada(le'lastics, adances in nuclear waste 'rocessin, etc.

• +earning rom !ature9 shells and (ioloical hard tissue can (e as stronas the most adanced la(oratory-'roduced ceramics, mollusces 'roduce

(iocom'ati(le adhesies that we do not know how to re'roduce"

• Materials for lihtweiht (atteries with hih storae densities, for tur(ine(lades that can o'erate at CA::B, room-tem'erature su'erconductors?chemical sensors 2arti&cial nose3 of e*tremely hih sensitiity, cotton shirtsthat neer reHuire ironin"

-uture o materials science



Materials of the Juture

Jour ty'es of materials used for smart actuator47. $ha'e memory alloysU metals, after hain (een

deformed, reert (ack to their oriinal sha'es whentem'erature is chaned.

C. )ieDoelectric ceramicsU e*'and and contract in res'onseto an a''lied electric &elds 2or oltae3U conersely,they also enerate an electric &eld when theirdimension are altered.

>. ManetostrictieU like 'ieDoelectric (ut in manetic&elds

F. /lectro-rheoloical maneto-rheoloical Ruids areliHuids that e*'erience dramatic chanes in iscosityu'on the a''lication of electric or manetic &elds.

bab 1 what are materials1

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