Introduction_SBIt is about materials enginerring course similar to william callister subject code is MT30001.It is our sirs slides iam from iit kgp.pdft

It is about materials enginerring course similar to william callister subject code is MT30001.It is our sirs slides iam from iit kgp

1. Materials Engg.
MT30001
Metallurgical and Materials 
Engineering (MME) department
1

2. General introduction to Metallurgical 
and Materials Engineering
2

3. Why Materials are IMPORTANT
3
Aviation
Structures
Aerospace
Energy
storage
Biomaterials
Electronics
Automobiles

4. More niche applications of Materials
Metals/alloys are crucial in Metallurgy and 
Materials engineering
4

5. Types of materials based on STRUCTURES
5

6. Polycrystal:
high porosity
Polycrystal: low porosity
Optical: Transmittance
single crystal
6
Polyethylene (PE)
Polyethylene oxide (PEO)

7. 7
Nature Communicationsvolume 11,  Articlenumber: 1434 (2020)
Single‐crystal polymers (SCPs)
highly ordered
continuous crystal lattice 
structure ‐entire sample,
lack grain boundaries.
Not amorphous or 
semicrystalline
SCPs are grown under specific 
conditions to achieve this high 
degree of crystallinity.
These crystals exhibit unique 
properties due to their uniform 
structure
Can be synthesized in various 
architectures, including 1D, 2D, 
and 3D.

8. 8
Glass, CR‐39 plastic Polycarbonate
For opacity
incorporate additives, adjust processing 
methods, or apply surface treatments.
Trivex
– Amorphous and 
optically clear

9. Metallurgical and Materials 
Science & Engineering
What does each of these terms mean?
Engineering: Designing and tailoring a certain process 
to obtain specific structure in the materials 
that produces a set of pre‐determined properties 
for performance during application
Science: Investigate the relationships
Technology: Outcome
9

10. Materials Engineering:
Selecting the right material
‐Performance in service condition
‐Performance over long run
‐Cost effectiveness
Designing and solving problem involving materials:
Transmission gear, Oil refinery component, Aero‐
Engine components, Integrated Circuit chips
Optimization of the properties
Correlating Processing – Structure –
Properties
Proficient and Confident in
judiciousselectionofmaterials
10

11. Structure‐mechanical property relationships
11
Carbon fiber reinforced polymer
Glass fiber reinforced polymer
Poly‐ether ether ketone
Polyamide
Polycarbonate
Poly‐methyl Meth‐acrylate
polyethylene terephthalate
Polypropylene
polyethylene

12. Structure‐dependent interesting mechanical property
12
oGrapheneis a hexagonal form of 
‘Carbon’, the same element which makes 
‘Diamond’ and every living being!
oGraphene has a Young’s modulus of 1000 GPa, and a tensile 
strength of 100 GPa. It is 300×STRONGER than STEEL.
oIt would take an elephant, standing on a pencil to break 
through a Graphene sheet!!!!!!!!!!!!!!!!!
C
Graphene
C
C
C
C
C
C
C
C
C
C
C
C
C
C

13. Graphite
Very weak atomic bonding
Very strong 
covalent atomic 
bonding 
Graphene
Very strong  covalent atomic  bonding of Carbon 
Diamond
Graphene is the strongest material ever recorded, more than 300  times 
stronger than the strongest A36 structural steel,  at 130 gigap ascals, and more 
than forty times stronger than diamond.
https://www.graphenea.com/pages/graphene‐graphite#.Yfoicd9BxPY

14. Structure
14
: Arrangement of material’s internal components
Subatomic:•Atomic
MicrostructureMacrostructure

15. Optical microscope
15
Property of materials: defining role of microstructure
1000 µm= 1 mm

16. 16
Rayleigh's criterion
θ = 1.22λ/D
λ =400 nanometers (violet) to 700 nanometers (red)
1 nm = 1 x 10^‐6 mm = 1 x 10^‐7 cm = 1 x 10^‐9 m 

17. 17
x=1.22λ/2sinα= 0.61λn/NA 
NA=n.sinα
n = refractive index of the lens
sinα=D/2d
The resolution limit is 
approximately 0.25 μm1000X
x=1.22λd/D

18. Scanning Electron Microscope
18
Property of materials: defining role of microstructure
1000 µm= 1 mm

19. High Resolution Transmission 
Electron Microscope
Individual 
atoms
19
Property of materials: defining role of microstructure
1000 nm =1 µm

20. RD
TD
20
Property of materials: Quantitative microstructure
Electron back scattered 
diffraction (EBSD) of pure 
Titanium in Scanning 
electron microscope  
(SEM)  TEXTURE
Crystallographic Orientation

21. Individual vibrating
atoms
Science372.6544 (2021): 826-831
21
Property of materials: defining role of microstructure Video
CCMR
Cryo STEM 
(Cornell)

22. Important Material properties for various applications
oHardness
oStrength
oModulus
oDuctility
oFracture Toughness
oImpact toughness
oWeldability
oFormability
oWear resistance
oFatigue resistance
oCreep resistance
oDamping
Electrochemical
oCorrosion resistance
oOxidation resistance
Physical
oMelting point
oThermal conductivity
oElectrical conductivity
oMagnetic properties
oTransparency
oSonority
oOptical
Aesthetics
oSurface finish
oPaint ability
Mechanical
22
Functional
oShape memory 
effect
oPseudoelasticity

23. Titanic movie scene
Brittle vs Ductile materials and consequences
23

24. Tensile behavior of different 
engineering Materials
24
•Testing of ductile material: 
•Mild steel 
•Copper  
•Testing of Brittle material: 
•Fe‐Al alloy

25. 25
•Mild Steel specimen: Total length= 100 mm, G (l
0
) = 25 mm, D = 5 mm
•Copper specimen: Total length= 100 mm, G = 25 mm, D = 6 mm
•Fe‐Al alloy flat specimen:   L = 100 mm, 
G = 25 mm, W = 6 mm and T = 3 mm.
Cylindrical Sample geometry
Flat Sample geometry

26. 26
Mild Steel Specimen
Copper Specimen
Fe‐Al Specimen (Brittle)

27. Engineering Stress and Engineering Strain
27
•Engineering Stress 
S = Load/Initial Area
PP
Gauge portion
PP
Initial cross 
section area
•Engineering Strain: 
Ratio of change in length 
(displacement) w.r.t.the 
original length.
e =

l/l
0
?
?
,
?
4
??
?
,
?
?
??
,
?
,
?
?
?
,

28. Engineering strain, e
Engineering stress, S
S
y
S
f
S
u The engineering stress (S) vs. 
engineering strain (e) curve for a 
ductile metal.
e
u
e
f
0.2 % strain offset
(e=0.002)
Loading and unloading curves showing the 
recoverable elastic deformation (b, d) and 
permanent plastic deformation (a, c).Typical Engineering Stress vs. Engineering Strain curves for 
a ductile metal

29. 29
Elastic limit
Engineering Stress‐Strain Curve
Elastic Limit:The point up to which
material shows elastic behaviour, i.e.,
displacement becomes zero as the
loadisremoved.
Immediately after elastic limit
permanentplasticdeformationstarts.
Elasticlimit,however,isextremely
difficulttodetectastheamountof
permanentdeformationjustafterthat
point is very very small. Therefore,
elastic limit is not determined for
engineeringapplication.

30. 30
Engineering Stress‐Strain Curve
•0.2% Offset Yield Strength, S
o
•Tensile Strength or Ultimate 
tensile strength, UTS, S
u
•Uniform Strain, e
u
•Strain to Fracture, e
f
Yield Strength:Pointatwhichsmall
but detectable or measurable
amount of plastic deformation
occurs.
Ultimate tensile strength (UTS) :It is the
maximum engineering stress
corresponding to the ‘point of maximum
load’. At UTS, the specimen becomes
instable and necking occurs ‐failure
becomesinevitable.

31. Engineering Stress‐Strain Curve
31
Uniform elongation (e
u
):Uniform
elongation is a measure of ductility
from manufacturing point of view.
??????
?
L
?
?
??
?
?
?
H100.
Elongation to failure (e
f):Ductility, i.e.,
deformability of a metal is generally
represented by total elongation to
failure.??????
?
L
?
?
??
?
?
?
H100.
e
u
is a very important requirement.
For eg., Ability for drawing a rod into
thin wirewithout the breaking.
Manufacturing of beverage can by deep drawing of 
sheet metals is a biaxial loading process requires 
High anisotropy i.e., strong crystallographic texture
Larger e
u
and delay in localized necking
Elastic limit

32. Reduction in area till fracture (%):
??????
?
L
?
,
??
?
?
?
H100.
Resilience:Ability of the material to
absorb energy when deformed
elastically and to return to it when
unloadediscalledResilience.
Toughness:Ability of the material to
absorb energy in the plastic range =
Areaunderthestress‐straincurve
Important Terminologies
32

33. Mild Steel exhibits yield point phenomenon Easy to identify yield
point.
Some important points on the Stress –Strain curve
33
Engineering Stress
Engineering Strain
2
2
1
3
1
3
IMPORTANTPOINTS:
For structural applications
the applied stress cannot
exceed YSAs the
structure will deform
permanently.
During manufacturing
plastic deformation is
required and applied
stress has to be higher
thantheYS.

34. •TrueStress:??????L
??????
??????
??????
;
•TrueStrain(??????):
Theinstantaneousstrainisthechangeingaugelengthatanyinstant
oftime,i.e.,????????????L
∆??????
??????
??????
.
Byintegrationwefind,truestrain,
??????L????????????
??????
?????? ??????
where,A
i
is the minimum cross‐sectional area of the gauge at any
instant,dlis the change in length over an instant of time when the
instantaneousgaugelengthisl
i.
34
True Stress and True Strain

35. Relation between stress and strain
l
0
×A
0
= l×A

A
0
/A = L/L
0
True Stress
??????L??????
??????E?????? is valid up to necking
•True Strain
35
P P
A
0
During plastic deformation  volume remains constant 
?
?
,
?
,
?
?
?
,

4
??
?
?
?
,
?
?
,

36. Comparison between engineering stress‐strain and true stress‐st rain 
curves. 
(Elastic deformation is very small, and hence, ignored)
Why such a difference?
Follow the next slides

37. Question:Why true stress – true strain curve is different from the engineering stres s‐
strain curve?
Answer:Apointontruestress‐truestraincurveliesaboveandattheleftofengg.
stress‐ engg. strain curve. The eqs. defining true stress, true strain, en gg stress, and
enggstrain(givenabove)canbereferredtounderstandthisaspect.
Forplasticdeformationtohappen,stressincreasescontinuouslytoincr easetheplastic
strain and that phenomenon is called ‘ strain hardening’. Therefore, true stress inside
the specimen increases continuously with the increase in strain at the def orming part
of the specimen. However, after a certain amount of uniform deformation, n ecking
happensandthefurtherdeformationoccursonlywithintheneckedregion.Underthis
instability condition, the cross‐sectional area of the necked region dec reases rapidly.
As the true stress is the ratio of load and instantaneous cross‐section are a. Even
though the load requirement decreases after necking, the instantaneous c ross‐section
area decreases much rapidly after necking. Resulting in the increase in tr ue stress.
Thus, beyond the point of maximum load (i.e., the UTS point), the engineeri ng stress
decreases as it is defined as load divided by a constant (initial cross‐sec tional area of
thespecimen).
37
Also,afterthepointofmaximumload,another
correction corresponding to specimen shape
changesduetoneckingisrequiredtobe
incorporatedintruestress–truestraincurve.

38. •Question:
How a tensile test specimen of ductile material looks 
like during different stages of plastic deformation?
38

39. 39
Zig‐Zag path
Necking accompanied by Void and crack formation

40. •Question:How to distinguish between a ductile material and 
a brittle material just by seeing the fractured specimens?
•Answer:Ductile material typically undergoes either through 
ductile rupture or cup‐and‐cone fracture with dull 
appearance on fracture surface. In contrast, a brittle material  
typically shows flat‐fracture surface with shiny appearance.
40
Brittle 
(Flat)
Ductile Single 
Crystals (by 
Shearing)
Ductile fracture in 
Polycrystalline Metals & 
Alloys

41. Distinct features in fracture surfaces
41
Cup and Cone Ductile 
Fracture
Flat and Shiny Brittle 
Fracture
Metallic Alloys

42. Thank You
42