1

Mat

eria

ls S

cien

ce

Intr

oduc

tion

2

�M

ater

ials

Sci

ence

:�

Invo

lves

inve

stig

atin

g th

e re

latio

nshi

p th

at

exis

t bet

wee

n th

e st

ruct

ure

and

prop

ertie

s of

mat

eria

ls.

By

stru

ctur

e w

e m

ean

the

arra

ngem

ent o

f its

inte

rnal

com

pone

nts

�M

ater

ials

En

gin

eeri

ng

:�

On

the

basi

s of

str

uctu

re-p

rope

rty

corr

elat

ions

, inv

olve

s de

sign

ing

or

engi

neer

ing

the

stru

ctur

e of

mat

eria

l to

prod

uce

a pr

edet

erm

ined

set

of p

rope

rtie

s

3

�P

rope

rty

is a

mat

eria

l tra

it in

term

s of

the

type

an

d m

agni

tude

of r

espo

nse

to a

spe

cific

im

pose

d st

imul

us.

The

pro

pert

y of

a m

ater

ial

is in

depe

nden

t of i

ts s

hape

and

siz

e

�T

here

are

six

cat

egor

ies

of m

ater

ial p

rope

rtie

s:

1.M

ech

anic

al p

rop

erti

es

4

2.E

lect

rica

l pro

per

ties

3.T

her

mal

pro

per

ties

4.M

agn

etic

pro

per

ties

5

5.O

pti

cal p

rop

erti

es

6.D

eter

iora

tive

pro

per

ties

6

Str

uct

ure

Pro

per

ties

Pro

cess

ing

Per

form

ance

Inte

rrel

atio

n b

etw

een

fo

ur

com

po

nen

ts o

f M

ater

ials

Sci

ence

7

�W

hy s

tudy

Mat

eria

ls S

cien

ce?

�E

ngin

eers

, whe

ther

mec

hani

cal,

civi

l, or

el

ectr

ical

will

at o

ne ti

me

or a

noth

er b

e ex

pose

d to

a d

esig

n pr

oble

m in

volv

ing

mat

eria

ls.

Exa

mpl

es, g

ear

build

ing,

oil

refin

ery

com

pone

nt, o

r an

inte

grat

ed c

ircui

t ch

ip.

�A

deq

uat

e kn

ow

led

ge

in m

ater

ials

an

d

allo

ws

an e

ng

inee

r to

pro

per

ly s

elec

t th

e b

est

mat

eria

l fo

r a

giv

en d

esig

n o

r ap

plic

atio

n.

8

�C

hap

ters

Co

vere

d�

Intr

oduc

tion

�A

tom

ic S

truc

ture

s an

d B

ondi

ng�

Cry

stal

line

Str

uctu

res

�D

efec

ts in

Sol

ids

�M

echa

nica

l Pro

pert

ies

�M

ater

ial F

ailu

re�

Pha

se D

iagr

ams

�E

ngin

eerin

g A

lloys

�P

olym

ers

�C

orro

sion

�N

on D

estr

uctiv

e T

estin

g

9

�B

asic

Cla

ssifi

catio

ns o

f Mat

eria

ls:

�C

lass

ifica

tion

are

mos

tly b

ased

on

chem

ical

mak

eup

and

atom

ic s

truc

ture

1.M

etal

2.C

eram

ic3.

Po

lym

er

�A

dditi

onal

Cla

ssifi

catio

ns o

f Mat

eria

ls:

1.C

om

po

site

s2.

Ad

van

ced

mat

eria

ls

10

�M

etal

s�

Com

pose

d of

one

or

mor

e m

etal

lic

elem

ents

, and

ofte

n no

n-m

etal

lic e

lem

ents

in

sm

all a

mou

nts.

�A

tom

s ar

e ar

rang

ed in

mor

e or

derly

m

anne

r.�

Pos

ses

good

stif

fnes

s, s

tren

gth

and

frac

ture

res

ista

nce.

�Lu

stro

us a

ppea

ranc

e.�

Not

tran

spar

ent t

o vi

sibl

e lig

ht.

�H

ighe

r de

nsity

com

pare

d to

pol

ymer

s an

d ce

ram

ics.

11

�S

uper

ior

elec

tric

al a

nd th

erm

al c

ondu

ctiv

ity.

�La

cks

corr

osio

n re

sist

ance

.�

Hig

h m

eltin

g po

int.

�S

ome

met

als

are

mag

netic

.

12

�S

om

e A

pp

licat

ion

of

Met

als

�E

lect

rical

wiri

ng�

Bui

ldin

g an

d br

idge

str

uctu

res

�A

utom

obile

: bod

y, c

hass

is, e

ngin

e bl

ock,

sp

rings

�A

ir pl

anes

: eng

ines

, fus

elag

e, la

ndin

g ge

ar�

Tra

ins:

rai

ls, e

ngin

e bo

dy, w

heel

s�

Indu

stria

l mac

hine

ry�

Mac

hini

ng to

ols:

dril

ls, h

amm

ers,

saw

bla

de�

Mag

nets

13

�C

eram

ics

�C

ompo

unds

of m

etal

lic a

nd n

on m

etal

lic

elem

ents

.�

En

gin

eeri

ng

cer

amic

sar

e m

ostly

oxi

des,

ni

trid

es a

nd c

arbi

des

e.g.

alu

min

ium

oxi

de,

silic

on d

ioxi

de, s

ilico

n ca

rbid

e, s

ilico

n ni

trid

e.�

Tra

dit

ion

al c

eram

ics

incl

ude

clay

, cem

ent

and

glas

s.�

Stif

fnes

s an

d st

reng

ths

that

are

com

para

ble

to m

etal

s.

14

�H

ard

and

britt

le a

nd v

ery

susc

eptib

le to

fr

actu

re.

�T

here

are

cer

amic

s w

hich

are

tran

spar

ent,

tran

sluc

ent a

nd o

paqu

e.�

Low

ele

ctric

al c

ondu

ctiv

ity.

�G

ood

resi

stan

ce to

hig

h te

mpe

ratu

res.

�G

ood

corr

osio

n re

sist

ance

.�

Som

e ar

e m

agne

tic.

�Lo

wer

den

sity

than

met

als.

15

�S

ome

App

licat

ion

of C

eram

ics

�E

lect

rical

insu

lato

rs�

The

rmal

insu

latio

n an

d co

atin

g�

Abr

asiv

es�

Gla

sses

: win

dow

s, T

V s

cree

ns, o

ptic

al fi

ber

�C

emen

t, co

ncre

te�

Cer

amic

tile

s�

Fur

nace

lini

ng b

ricks

16

�P

olym

ers

�O

rgan

ic c

ompo

unds

that

are

che

mic

ally

ba

sed

on c

arbo

n , h

ydro

gen

and

othe

r no

n-m

etal

lic e

lem

ents

.�

The

y ha

ve la

rge

mol

ecul

ar s

truc

ture

s, o

ften

chai

n lik

e.�

Com

mon

pol

ymer

s in

clud

e po

lyet

hyle

ne,

nylo

n, p

olyv

inyl

chl

orid

e, p

olyc

arbo

nate

and

po

lyst

yren

e.�

Low

er d

ensi

ty th

an m

etal

s an

d ce

ram

ics.

�La

cks

stiff

ness

and

str

engt

h.�

Ext

rem

ely

duct

ile

17

�G

ood

corr

osio

n re

sist

ance

.�

Low

er m

eltin

g po

int –

easi

ly s

ofte

ns o

r de

com

pose

s.�

Low

ele

ctric

al c

ondu

ctiv

ities

.�

Not

mag

netic

.�

Som

e po

lym

ers

are

tran

spar

ent b

ut m

ost

are

opaq

ue.

18

�S

om

e A

pp

licat

ion

s o

f P

oly

mer

s�

Adh

esiv

e an

d gl

ue�

Pla

stic

pro

duct

s�

Coa

ting

and

pain

ts�

Sol

id lu

bric

ants

: Tef

lon

�S

ealin

g: g

aske

t, o-

rings

, liq

uid

seal

s�

Clo

thin

g an

d fu

rnitu

re c

over

ing

19

�C

om

po

site

s�

Com

pose

d of

two

or m

ore

indi

vidu

al

mat

eria

ls i.

e. m

etal

, cer

amic

or

poly

mer

.�

Des

igne

d to

ach

ieve

a c

ombi

natio

n of

pr

oper

ties

not p

osse

ssed

by

a si

ngle

m

ater

ial.

�S

ome

natu

rally

occ

urrin

g co

mpo

site

s in

clud

e w

ood

and

bone

.�

Com

mon

com

posi

te in

clud

es fi

breg

lass

(s

mal

l gla

ss fi

bres

em

bedd

ed w

ithin

po

lym

eric

mat

eria

l)

20

�T

he g

lass

fibr

es a

re r

elat

ivel

y st

rong

, stif

f an

d br

ittle

but

the

poly

mer

is d

uctil

e, w

eak

and

flexi

ble.

Thu

s th

e co

mpo

site

of t

he tw

o is

a r

elat

ivel

y st

iff, s

tron

g, fl

exib

le a

nd

duct

ile fi

breg

lass

.

21

�S

ome

App

licat

ion

of C

ompo

site

s�

Aer

ospa

ce, M

arin

e, A

utom

otiv

e�

Spo

rtin

g go

ods

�S

tora

ge ta

nks

�C

oatin

g�

Pip

ing

for

oil,

seaw

ater

, sew

age

22

�A

dva

nce

d M

ater

ials

�M

ater

ials

that

are

util

ized

in h

igh-

tech

nolo

gy a

pplic

atio

ns a

re s

omet

imes

te

rmed

adv

ance

d m

ater

ials

. �

Hig

h te

chno

logy

: a d

evic

e or

pro

duct

that

op

erat

es u

sing

rel

ativ

ely

com

plex

and

so

phis

ticat

ed p

rinci

ples

. E.g

. ele

ctro

nic

equi

pmen

t (V

CR

s, C

D p

laye

rs, e

tc.)

, co

mpu

ters

, fib

erop

tic s

yste

ms,

spa

cecr

aft,

airc

raft,

and

mili

tary

roc

ketr

y.

23

�T

ypic

ally

trad

ition

al m

ater

ials

who

se

prop

ertie

s ha

ve b

een

enha

nced

OR

new

ly

deve

lope

d, h

igh-

perf

orm

ance

mat

eria

ls.

�T

hey

may

be

of a

ll m

ater

ial t

ypes

(e.

g.,

met

als,

cer

amic

s, p

olym

ers)

.�

Nor

mal

ly r

elat

ivel

y ex

pens

ive.

24

the end