jif 104_lesson 4.pptx

7/25/2019 JIF 104_Lesson 4.pptx

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Siri e-Kuliah PPPJJ, USM

JIF 104Physics II

Introduction to Basic Material

ScienceDr. Nor Zakiah Binti Yahaya

Lesson 4


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What is materialsscience?

structures Properties of Materials

i)Electrical

ii)Magneticiii)Thermaliv)Opticalv)Mechanical


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Outlines Properties of Materials

i)Electrical

ii)Magneticiii)Thermal

iv)Optical

v)Mechanical

Classification of materials


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PROPERTIES OF MATERIALS

Unit 4.


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Properties are the way the material responds to the

environment and external forces

!esponse to mechanical forces"strength" etc.Mechanical

!esponse electrical an# magneticfiel#s" con#uctivit$" etc.Electrical an#Magnetic

!elate# to transmission of heat an#heat capacit$.Thermal

%nclu#e to a&sorption" transmission an#scattering of light.Optical

%n contact 'ith environment ( corrosionresistanceChemical


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OPT%CLP!OPE!T%E*


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W e l e a d Material ( Light

interaction%nteraction of photons 'ith the electronic

or cr$stal structure of a material lea#s to

a num&er of phenomena.

The photons ma$ givetheir energ$ to the

material +a&sorption),

photons give their energ$"&ut photons of i#enticalenerg$ are imme#iatel$emitte# &$ the material

+reflection),

photons ma$ notinteract 'ith the materialstructure +transmission),

Or #uring transmissionphotons are changes in

velocit$ +refraction).


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%ntensit$ of the inci#ent lightt an$ instance of light interaction 'ith a

material" the total intensit$ of the inci#ent

light stri-ing a surface is eual to sum ofthe a&sor&e#" reflecte#" an# transmitte#

intensitiesi.e.


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W e l e a d Optical materials

Materialsare

classifie#on the &asisof their

interaction'ith visi&lelight into

three

categories.

transparent

Materials that are capa&le of transmitting

light 'ith relativel$ little a&sorption an#reflection

i.e. 'e can see through them

Translucent

i.e. o&/ects are not clearl$#istinguisha&le 'hen vie'e# through.

Translucent materials are thosethrough 'hich light is transmitte#

#iffusel$

opaue

Those materials that are impervious tothe transmission of visi&le light

These materials a&sor& all the energ$from the light photons.


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W e l e a d Optical properties 0 Metals

Metals consist partiall$ fille# high0energ$con#uction &an#s.

When photons are #irecte# at metals" their

energ$ is use# to e1cite electrons intounoccupie# states. Thus metals are

opaue to the visi&le light.

Metals are" ho'ever" transparent to high

en# freuencies i.e. 10ra$s an# 20ra$s.


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W e l e a d Optical properties 0 Metals

&sorption of ta-es place in ver$ thin outer

la$er. Thus" metallic films thinner than 3.

m can transmit the light.

The a&sor&e# ra#iation is emitte# from the

metallic surface in the form of visi&le light

of the same 'avelength as reflecte# light.The reflectivit$ of metals is a&out 3.56.


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Optical properties of metals


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Optical properties ( 7on0metals

7on0metallic materials consist of variousenerg$ &an# structures. Thus" all four

optical phenomena are important.

a&sorption reflection

transmission refraction


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M87ET%CP!OPE!T%E*


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magnetism

iama!netism

Parama!netism

ferroma!netism


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iama!netism

ver$ 'ea- form of magnetism that is nonpermanent an# persists onl$ 'hile

an e1ternal fiel# is &eing applie#.

%t is in#uce# &$ a change in the or&ital motion of electrons #ue to an applie#magnetic fiel#.

9iamagnetism is foun# in all materials, &ut &ecause it is so 'ea-" it can &e

o&serve# onl$ 'hen other t$pes of magnetism are totall$ a&sent. This form

of magnetism is of no practical importance

Fi!"re #$%& +a) The atomic

#ipole configuration for a#iamagnetic material 'ith an#

'ithout a magnetic fiel#. %n the

a&sence of an e1ternal fiel#" no

#ipoles e1ist,

in the presence of a fiel#" #ipoles

are in#uce# that are aligne#

opposite to the fiel#

#irection.


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Parama!netism

:or some soli# materials" each atom possesses a permanent #ipole

moment &$ virtue of incomplete cancellation of electron spin an#;or

or&ital magnetic moments. %n the a&sence of an e1ternal magnetic fiel#" the orientations of these

atomic magnetic moments are ran#om" such that a piece of material

possesses no net macroscopic magneti


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W e l e a d ferroma!netism

Certain metallic materials possess a permanent magnetic moment in

the a&sence of an e1ternal fiel#" an# manifest ver$ large an#

permanent magneti


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ferroma!netism Permanent magnetic moments in ferromagnetic materials result

from atomic magnetic moments #ue to electron spin>uncancelle#

electron spins as a conseuence of the electron structure. There is

also an or&ital magnetic moment contri&ution thatis small in comparison to the spin moment. :urthermore" in a

ferromagnetic material" coupling interactions cause net spin

magnetic moments of a#/acent atoms to align 'ith one another"

even in the a&sence of an e1ternal fiel#.


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MEC7%CLP!OPE!T%E*


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Tensile stren!th( measures

the force reuire# to pull

something such as rope"'ireor a structural &eam to the

point 'here it &rea-s

"ctility( a measure of ho'

much strain a material can

ta-e &efore rupturing

Mechanical properties


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Mallea(ility( the propert$ of

a material that can &e 'or-e#

or hammere# or shape#'ithout &rea-ing

)rittleness(&rea-ing orshattering of a material 'hen

su&/ecte# to stress +'hen

force is applie# to it)



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Elasticity( the propert$ of a

material that returns to its original

shape after stress +e.g. e1ternalforces) that ma#e it #eform or

#istort is remove#

Plasticity0 the #eformation of amaterial un#ergoing non0

reversi&le changes of shape in

response to applie# forces



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Machina(ility( the propert$ of a material

that can &e shape# &$ hammering"

pressing" rolling



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To"!hness( the a&ilit$ of a

material to a&sor& energ$ an#

plasticall$ #eform 'ithoutfracturing

*ardness( the propert$ of&eing rigi# an# resistant to

pressure, not easil$ scratche#



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ELECT!%CL 79M87ET%C

P!OPE!T%E*


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Relative permittivity( its #ielectric

permittivit$ e1presse# as a ratio relative to

the permittivit$ of vacuum.

ielectric Stren!th( #epen#ent on the

configuration of the material or theelectro#es 'ith 'hich the fiel# is applie#.

Electrical Properties


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Electrical resistivity0 an intrinsic

propert$ that uantifies ho'

strongl$ a given material opposesthe flo' of electric current.

Electrical cond"ctivity0 thereciprocal of electrical resistivit$"

an# measures a material@s a&ilit$

to con#uct an electric current.



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Pie+oelectricity0 the electric charge that

accumulates in certain soli# materials

+such as cr$stals" ceramics" an# &iologicalmatter such as &one)in response to

applie# mechanical stress.



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,"rie temperat"re+Tc) 0 the temperature

'here a material@s permanent magnetism

changes to in#uce# magnetism.

iama!netic 0 create an in#uce#

magnetic fiel# in a #irection opposite to an

e1ternall$ applie# magnetic fiel#" an# are

repelle# &$ the applie# magnetic fiel#.

Magnetic Properties


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*ysteresis0 the #epen#ence of the

output of a s$stem not onl$ on its current

input" &ut also on its histor$ of past inputs.

Permea(ility0is the measure of the a&ilit$

of a material to support the formation ofa magnetic fiel# 'ithin itself.

Magnetic Properties


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TE!MLP!OPE!T%E*


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Specific heat( the heat reuire# to raise

the temperature of one gram of a

su&stance &$ one #egree centigra#e +A;-gB)

Thermal cond"ctivity(rate at 'hich heatflo's through a given material +W;m B)

Thermal Properties


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Meltin! point( a temperature at 'hich a

soli# &egins to liuif$

,oefficient of thermal expansion(

#egree of e1pansion #ivi#e# &$ the

change in temperature +m;C)

Thermal Properties


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OPT%CLP!OPE!T%E*


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,olo"r0 the visual perceptual

propert$ correspon#ing in humans to the

categories calle# red" blue" yellow" an#others.

Photosensitivity0the amount to 'hich ano&/ect reacts upon receiving photons"

especiall$ visi&le light.

Optical Properties


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Reflectivity0 the fraction of inci#ent

electromagnetic po'er that is reflecte# at

an interface" in contrast to the reflectioncoefficient" 'hich is the ratio of the

reflecte# to inci#ent electric fiel#.

Refractive index 0 #escri&es ho' light" or

an$ other ra#iation" propagates through

that me#ium.

Optical Properties


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Transmittance0 the fraction of inci#ent

light +electromagnetic ra#iation) at a

specifie# 'avelength that passes througha sample

Optical Properties


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CEM%CLP!OPE!T%E*


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,orrosion resistance - a material@s a&ilit$

to resist #eterioration cause# &$ e1posure

to an environment

S"rface ener!y0 uantifies the #isruption

of intermolecular &on#s that occur 'hen asurface is create#.

Chemical Properties


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,LASSIFI,ATIO. OFMATERIALS

Unit .D


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Metals Ceramics Pol$mers Composites



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Metals valence electrons

are #etache# fromatoms" an#sprea# in an

electron seaF thatgluesF the ionstogether. Metalsare usuall$ strong"con#uct electricit$an# heat 'ell an#are opaue tolight +shin$ of

polishe#). E1amplesGaluminium" steel"&rass" gol#.


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Metals


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Ceramicstoms &ehave

mostl$ li-e eitherHve or (ve ions"an# are &oun# &$Coulom& forces

&et'een them.The$ are usuall$com&inations ofmetals orsemicon#uctors'ith o1$gen"nitrogen" orcar&on +o1i#es"nitri#es an#

car&i#es). E1amplesG glass"

porcelain" man$minerals.


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Pol$mers

re &oun# &$covalent forcesan# also &$ 'ea-van #er Waals

forces" an#usuall$ &ase# on" C an# othernon0metallicelements. The$#ecompose atmo#eratetemperatures +33C 400 C), and

are lightweight.therproperties var!greatl!.

"xamples#plastics $n!lon,

%e&on,pol!ester) and

rubber.


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Composites 7ot &ase# on

&on#ing. Thecomposites ma#eof #ifferentmaterials an#

intimate contact. E1amplesG

fi&erglass"concrete" 'oo#) toachieve specificproperties.

f i l


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W e l e a d Types of Materials

Metals:

Strong, ductile High thermal & electrical conductivity

Opaque, reflective.

Polymersplastics: !ovalent "onding sharing of electrons Soft, ductile, lo# strength, lo# density

Thermal & electrical insulators

Optically translucent or transparent.

!eramics: ionic "onding $refractory% compounds of metallic& non'metallic elements $o(ides, car"ides, nitrides, sulfides% )rittle, glassy, elastic

*on'conducting $insulators%


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*ourceG httpG;;'''.livetra#ingne's.com;lme0&ase0metals0close0higher0as0mar-et0

e1pects0ec&0stimulus0action0IJD4I.htmK.-NNtBU#u

Metals

:errous metalsan# allo$s +irons"car&on steels"allo$ steels"stainless steels"tool an# #iesteels)

7onferrousmetals an# allo$s+aluminium"copper"magnesium"nic-el" titanium"precious metals"refractor$ metals"

super allo$s)


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httpG;;'''.4csla&orator$.com;gem0info;#iamon#;

Ceramics

8lasses 8lass ceramics 8raphite 9iamon#

8lasses 8raphite

9iamon# 8lass ceramics0 coo-top


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Pol$mers

Thermoplasticsplastics

Thermosetplastics

elastomers

Elastomers

*ourceGhttpG;;'''.a#hesivean#glue.com;elastomer.html


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Composites

!einforce#plastics

Metal0matri1composites

Ceramic0matri1composites

*an#'ich

structures concrete

9ifferent materials can

&e com&ine# to create a

composite material.

Composite materials are

groupe# &$ the t$pes of

materials com&ine# or

the 'a$ the materials are

arrange# together.

Metal0matri1 composites

concrete

!einforce# plastics


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*ummar$


Metals

Strong, ductile

High thermal &electrical

conductivity

Opaque,reflective.

Ceramics

)rittle, glassy,

elastic*on'

conducting$insulators%

Pol$mers

Soft, ductile, lo#

strength, lo# densityThermal & electrical

insulators

Optically translucent ortransparent.

Composites


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Than- $ou

jif 104_lesson 4.pptx

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