What is known as the ability of a material to undergo significant plastic deformation before rupture?

The ability of a material to undergo significant plastic deformation before rupture is referred to as toughness. Toughness is a crucial property of materials, particularly when considering their performance under stressful conditions. It measures the amount of energy a material can absorb before failing. This is important in applications where materials must withstand impacts or sudden loads without fracturing. A tough material can deform considerably and still retain the ability to absorb energy without breaking.

Resilience, while related, specifically describes a material's ability to absorb energy when deformed elastically and release that energy upon unloading, rather than undergoing plastic deformation. Relaxation refers to a material's tendency to decrease stress under constant strain over time, which does not pertain to plastic deformation before rupture. Elasticity relates to a material's ability to return to its original shape after being deformed, but it does not account for significant plastic deformation or energy absorption before breaking.