This document provides an overview of the properties and characteristics of engineering materials, categorizing them into physical, mechanical, and chemical properties. Key physical properties include density, specific gravity, and thermal conductivity, while mechanical properties focus on strength, toughness, and hardness. Chemical properties involve aspects like chemical composition, atomic bonding, and corrosion resistance.

1. Properties
And Characteristics of
Materials

2. Introduction
Materials are classified and the most
important properties of the
engineering materials are listed with

3. Properties:
Physical
Mechanical
Chemical

4. Physical
The physical properties of
a material are those which
can be observed without
change of the identity of
material.

5. Typical Properties:
 Density
 Specific gravity
 State Change
temperatures
 Coefficients of
thermal expansion
 Specific Heat
 Latent heat
 Fluidity
 Weld ability
 Elasticity
 Plasticity
 Porosity
 Thermal
conductivity
 Electrical
Conductivity

6. Density
 A material or substance is
defined as “the mass per unit
volume”. It is represented as
the ratio of mass with volume
of a material.
Density-

7. Specific gravity
 It is defined as the ratio of
density of material with respect
to density of a reference
material or substance. For
gravity calculation generally
water is considered as a
reference substance.

8. State Change temperatures
 Generally a substance is having
three states called – solid state,
liquid state, gaseous state. State
change temperature is the
temperature at which the
substance changes from one
state to another state.

9. Coefficients of thermal
expansion
 When a material is heated, it expends, due
to which its dimensions change. Coefficient
of thermal expansion, represents the
expansion in material with increase of
temperature.

10. Specific Heat
 Specific heat of a material is defined
as the amount of heat required to
increase the temperature of unit
mass of material by 1°C. It is denoted
by ‘S’. Where, ‘m’ is the mass of
material in Kg. ‘Q’ is the amount of
heat given to material in Joule. ‘ t’ is
Δ
rise in temperature. Unit of specific
heat in SI system is, Joule/Kg °C

11. Latent heat
 Latent Heat of a material is defined as
the amount of heat required / released
by change the unit mass of material from
one state to another state (Phase
change). It is denoted by ‘L’. Latent heat
is given by Where, ‘Q’ is the amount of
heat required / released by material (in
joule), ‘m’ is the mass of material (in Kg).
Unit of Latent heat in SI system is Joule /
Kg.

12. Fluidity
 It is a property of material
which represents that how
easily a material can flow in
liquid state.

13. Weld ability
 It is the property of a material
which presents that how easily
the two pieces of material can
be welded together by applying
pressure or heat or both.

14. Elasticity
 It is the property of a material
by which it regains its original
dimensions on removal of load
or force.

15. Plasticity
 Increasing the load beyond
limit of elasticity material
retains it molded state.

16. Porosity
 When a material is in melting
condition, it contains some
dissolved gases with in the
material.

17. Thermal conductivity
 It is the property of a material
which represents that how
easily the heat can be
conducted by material.

18. Electrical Conductivity
 It is the property of material
which represents that how
easily the electricity can be
conducted by the material

19. Mechanical Properties
 The mechanical properties of a
material are those which effect the
mechanical strength and ability of
material to be molded in suitable
shape.

20. Typical Properties
 Strength
 Toughness
 Hardness
 Hardenability
 Brittleness
 Malleability
 Ductility
 Creep and Slip
 Resilience
 Fatigue

21. Strength
 It is the property of material
which opposes the deformation
or breakdown of material in
presence of external forces or
load

22. Toughness
 It is the ability of material to
absorb the energy and gets
plastically deformed without
fracturing.

23. Hardness
 It is the ability of material to resist to permanent
shape change due to external stress. measure of
hardness – scratch Hardness, indentation
hardness and rebound hardness
 Scratch Hardness is the ability of material to
oppose the scratch to outer surface layer due to
external force.
 Indentation Hardness It is ability of material to
oppose the dent due to punch of external had and
sharp object.
 Rebound Hardness is also called as dynamic
hardness. It is determined by the height of
“bounce”

24. Hardenability
 It is the ability of a material to
attain the hardness by heat
treatment processing. It is
determined by the depth up to
which the material becomes
hard.

25. Brittleness
 A material indicates that how
easily it gets fractured when it
is subjected to a force or load.

26. Malleability
 Is property of solid material
which indicates that how easily
a materials gets deformed
under compressive stress.

27. Ductility
 Is a property of a solid material
which indicates that how easily
a materials gets deformed
under tensile stress. Ductility is
often categorized by the ability
of material to get stretched into
a wire by pulling or drawing.

28. Creep and Slip
 The property of material which
indicates the tendency of
material to move slowly and
deform permanently under the
influence of external
mechanical stress.

29. Resilience
 Is the ability of material to
absorb the energy when it is
deformed elastically by
applying stress and release the
energy when stress is removed.

30. Fatigue
 Is the weakening of material
caused by the repeated loading
of material

31. Chemical Properties
 materials come into contact
of
other materials react
chemically to each other.

32. Types of Chemical
Properties
 Chemical composition
 Atomic bonding
 Corrosion resistance
 Acidity or Alkalinity

33. Chemical composition
 Indicates the
elements which are
combined together
to form that
material.
 Examples
 Steel
 Brass
 Bronze
 Invar
 Gun Metal
 German Silver or
Nickel Silver or
Electrum
 Nichrome
 Phosphor Bronge
 Manganin
 Constantan

34. Atomic bonding
 Represents how atoms are
bounded to each other to form the
material.
 Ionic bonds
 Covalent bonds
 Metallic bonds

35. Corrosion resistance
 Is a gradual chemical or
electrochemical attack on a
metal by its surrounding
medium. Corrosion of a metals
is effected by many factors such
as air, industrial atmosphere,
acid, bases, slat solutions &
soils etc. Corrosion has a very
adverse effect on material.

36. Acidity or Alkalinity
 A material indicates that how
the react with other materials.