UNIT - 1

1. MECHANICAL PROPERTIES OF
MATERIALS
.

2. ELASTICITY
• The ability of the material to regain its original
shape after releasing the load
• EXAMPLE: STEEL AND RUBBER

3. Plasticity
• The ability of the material not to regain its
original shape after releasing the load
• EXAMPLE: CLAY

4. Ductility
• The ability of the material to drawn into wire
EXAMPLE: Gold, platinum, silver

5. Malleability
• The ability of the material to drawn in to
sheets.
• EXAMPLE: gold

6. Brittleness
• The ability of the material fracture without
deformation
EXAMPLE: Cast iron and glass

7. Hardness
• The ability of the material to resist abrasion,
indentation , machining and scratching.
• EXAMPLE: DIAMOND, QUARTZ AND GLASS

8. Toughness
• The ability of the material to absorb energy
and plastically deform without fracturing.
• EXAMPLE: MILD STEEL

9. Stiffness
• The ability of a material to resist deformation
against bending or loading
• The ratio of stress to the strain below elastic
limit.

10. Resilience
• The ability of the material to store energy and
resist shocks or impacts.
• Proof resilience
The maximum energy which can be stored in a
body up to the elastic limit is called proof
resilience.
*The proof resilience per unit volume is called
modulus of resilience

11. Creep
• A slow and permanent deformation in a
material under a steady load at constant
temperature.
• EXAMPLE: the property is considered in
turbines and IC engines.

12. Strength
• The ability of the material to withstand or
support an external force or load without
rupture.
• Elastic strength : It’s the value of load
corresponding to transition from elastic to
plastic range.
• Plastic strength : It’s the value of the load
corresponding to plastic range and rupture.

13. FATIGUE
• It deforms under the fluctuating or repeated
loads

14. Technological properties
.

15. Machinability
• The ability of the material to allow and
undergo various machining operations.

16. Castability
• The ability of the material to cast into
different shape and size.

17. Weldability
• The ability of the material to accept the
joining of two similar or dissimilar materials
during welding.

18. Formability or Workability
• The ability of the material to accept and
undergo the changes in shape and sizes.

19. FACTORS AFFECTING
MECHANICAL PROPERTIES
.

20. FACTORS
• Grain size
• Heat treatment
• Atmospheric exposure
• Low and high temperature.

21. Hooks law
• The stress is directly proportional to strain
with in the elastic limit