Question

material engineering

Q8: What are the main differences between toughness and resilience?

Answer 1

• When we apply the axial force to the specimen, it tends to elongate and deforms.

Stress-strain curve for elastic material :

71 Stress (N/mm) B L С Resilience Strain C%)

71 Stress (N/mm) E B F A Toughness Strain - C%)

• There are mainly three phases of deformation,

(1) Temporary deformation :- It is also known as Elastic deformation of the body. OA region in the stress- strain diagram shows the Temporary deformation.

(2) Permenent deformation :- It is also known as plastic deformation of the body. BF region in stress-strain diagram shows the permenent deformation.

(3) Fracture :- It is the last point on stress- strain diagram ( Point F ) and it is the point at which body breaks into two parts.

Now, Toughness :- It is the energy absorbed per unit volume of the body, when subjected to axial force till the Fracture point.

Resilience :- It is the energy absorbed per unit volume of the body, when subjected to axial force till the elastic point.

So, Toughness and Resilience both are energy absorbing Phenomena but for different regions.

So, We can say that Resilience is the area under the curve of stress-strain diagram till elastic point ( Point A ) and Toughness is the area under the curve of stress-strain diagram till fracture point.

So, Obviously Thoughness will be greater than the Resilience.

Resilience is considered when large elastic deformation is needed or desired and Toughness is important property of the material for different metal forming processes.