Basic of material characteristics

1. PRESENTED BY-
NAME - SOUMYABRATA BASAK
ROLL - 14MS06005
08/22/14 1
Engineering Materials and Properties

2. Definition Of Materials Of Engineering
Materials of Engineering refers to selecting the
correct materials for the application in which the
engineered part is being used. This selection
process includes choosing the material, paying
attention to its specific type or grade based on the
required properties.
SMMME 208/22/14

3. SMMME 3
Material Selection
Function
Material Shape
Process
Material selection and process cannot be separated from the shape
and the function of the product, two way interaction.
Function dictates the choice
of material and shape.
Process interacts
with shape.
Process is influenced
by material
Shape restricts the
choice of material
and process.
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4. SMMME 4
Engineering Materials Classification
Engineering Materials
Metals & Alloy Non Metals
Steel
Stainless steel
Cast iron
Ferrous Non-ferrous
Aluminum
Copper
Zinc
Titanium
Tungsten
Thermoplastics
Acrylic
Nylon
ABS
Polyethylene
Polycarbonate
PVC
Thermosets
Phenolic
Polymide
Polyester
Elastomers
Rubber
Polyurethane
Silicone
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5. SMMME 5
Engineering Materials
Materials
Metals Non Metals
Ceramics
Glass
Carbides
Nitrides
Oxides
Graphite
Diamond
Glasses
Glass ceramics
Composites
Reinforced
plastics
Metal-Matrix
Ceramic-Matrix
Laminates
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6. SMMME 6
Properties of Materials
Properties of Materials
Metallurgical/Mechanical Properties
Hardness
Hardness
Toughness
Fatigue (cyclic load)
Creep (temp / time)
Physical & chemical
Properties
Thermal conductivity
Thermal expansion
Electrical conductivity
Magnetic properties
Corrosion
Density
Melting point
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7. 7
• Tensile stress, σ: • Shear stress, τ:
Area, A
Ft
Ft
σ =
Ft
Ao
original area
before loading
Area, A
Ft
Ft
Fs
F
F
Fs
τ =
Fs
Ao
Stress has units: N/m2 or lb/in2
Engineering Stress
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8. 8
Engineering Strain
Strain is
dimensionless.
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9. SMMME 9
Material Strength
Standard Tensile Test
Standard Specimen
Ductile Steel (low carbon)
Sy – yield strength
Su – fracture strength
σ (stress) = Load / Area
ε (strain) = (change in length) / (original length)
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10. 10
F
δ
bonds
stretch
return to
initial
1. Initial 2. Small load 3. Unload
Elastic means reversible.
Elastic Deformation
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11. 11
1. Initial 2. Small load 3. Unload
Plastic means permanent.
planes
still
sheared
F
δelastic + plastic
bonds
stretch
& planes
shear
δplastic
Plastic Deformation (Metals)
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12. 1208/22/14 SMMME

13. (c)2003 Brooks/Cole, a division of Thomson Learning, Inc. Thomson Learning™ is a trademark used herein under license.
1. Localized deformation of a ductile material during a tensile test produces
a necked region.
2.The image shows necked region in a fractured sample
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14. SMMME 14
Material Strength
Different grade of steel Plastics
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Natural Rubber

15. SMMME 15
• - the extent of plastic deformation that a material undergoes
before fracture, measured as a percent elongation of a material.
% elongation = (final length, at fracture – original length) / original length
Ductility
Common Mechanical Properties
• – the
highest stress a material
can withstand and still
return exactly to its original
size when unloaded.
Yield Strength (Sy)
• - the
greatest stress a material can
withstand, fracture stress.
Ultimate Strength (Su)
• - the
slope of the straight portion of
the stress-strain curve.
Modulus of elasticity (E)
• - the capacity of a material to absorb energy within the elastic
zone (area under the stress-strain curve in the elastic zone)
Resilience
• - the total capacity of a material to absorb energy without fracture
(total area under the stress-strain curve in the elastic zone)
Toughness
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16. 08/22/14 SMMME 16
Metals
The most common materials characteristics which are useful in design,
production purpose in various Industries are :-
• Conduct electricity and heat.
• Have relatively high melting point, some metal alloys can
withstand temp. up to 2200 o
C.
• Metals are ductile, they can be shaped by extrusion (hot or
cold), rolling, forging and drawing.
• Metals are easy to machine with precision.
• Metals are strong, stiff, and tough.
• They can be made stronger by alloying and heat treatment.
• Metals are vulnerable to corrosion.

17. THANK YOU
08/22/14 SMMME 17

18. References
• www.wikipedia.org (collection of theory)
• www.google.com (photo collection)
• Materials Science And Engineering-
Callister’s
• Physical Metallurgy-V.Raghavan
• Mechanical Metallurgy-George E. Dieter
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19. THANK
YOU
08/22/14 SMMME 19