What is deformation in metal materials?

When metal materials are subjected to external forces and their shape and size change, this is called deformation.

Material deformation includes plastic deformation and elastic deformation.

For materials that deform, if the deformation disappears when the external force is removed, this is called elastic deformation.

If the deformation remains after the force is removed, it is called plastic deformation.

During service, components always experience some stress. The stress should not cause the material to undergo plastic deformation, otherwise it could lead to component failure.