Question

Toughness of a material increases, when ________ increases.
1. Strength
2. Fatigue resistance
3. Stress relieving
4. Machinability

Answer 1

Correct Answer - Option 1 : Strength

Explanation:

• Toughness is defined as the ability of the material to absorb energy before fracture takes place.
• This property is essential for machine components which are required to withstand impact loads.
• Tough materials have the ability to bend, twist or stretch before failure takes place.
• Toughness is measured by a quantity called modulus of toughness. Modulus of toughness is the total area under the stress-strain curve in a tension test.
• Toughness is measured by Izod and Charpy impact testing machines.
• When a material is heated it becomes ductile or simply soft and thus less stress is required to deform the material and stress-strain curve will shift down and area under curve decreases thus toughness decreases.
• Toughness decreases as temperature increases.
• Toughness of a material increases, when strength increases.