Toughness and Impact Strength of Metals
Toughness is the resistance to the impact loading against fracture. If a metals is tough, then it has the ability to store large strain energy before failure, deflection curve up to fracture stage.
Modulus of Toughness
It is the total strain energy per unit volume upto fracture stage. it is equal to the area under stress strain curve upto fracture. Generally, greater the toughness, greater will be the toughness. Therefore Mild Steel is more tough than High tensile steel.
Charpy impact test is used to Measures the amount of Energy Absorbed during fracture of a specimen in a standardized test. French scientist Georges Charpy developed test in 1905.