Ability of an orthodontic wire to spring back to its original shape is evaluated by:
Brittleness
Resilience
Tensile strength
Toughness
Popularly, the term resilience is associated with springiness, but it means precisely the amount of energy absorbed within a unit volume of a structure when it is stressed to its proportional limit. The resilience of two or more materials can be compared by observing the areas under the elastic region of their stress-strain plots assuming that they are plotted on the same scale. The material with  the larger elastic area has the higher resilience.
Phillips dental materials 12th edition page no 55