Definition - What does Resilience mean?
Resilience is the ability of a material to withstand elastic deformation without deforming plastically. In other words, resilience involves the stretching of atomic bonds prior to the breaking of the bonds. The maximum amount of volume that a material will elastically deform before becoming permanently deformed is known as the modulus of resilience.
Corrosionpedia explains Resilience
If a material is elastically deformed then its atomic bonds are stretched, but no bonds are broken. The material will return to its original state so long as the bonds are not broken and only elastic deformation has occurred. Resilience is an important material selection criterion for applications that require materials to be flexible under load, but return to their previous form once the load is removed.
It is important to note that resilience and toughness are two very different terms. Resilience is the ability of a material to deform elastically. Toughness is the ability of a material to absorb energy not only from elastic deformation, but from plastic deformation as well. When testing the resilience of a material, it will be possible to use it after the testing is complete. Testing the toughness of a material, however, is almost always destructive.
All materials have different moduli of resilience. Rubber is an example of a material that has an extremely high modulus of resilience. Ceramics typically have a very low modulus of resilience. In terms of metals, brass has a relatively high modulus of resilience, while a metal such as cast iron has a relatively low modulus of resilience.