peeneteralise metalse materjali võime purunemata deformeeruda olulises ulatuses (tavaliselt 200…1000 %) kõrgetel temperatuuridel (üle rekristallisatsioonitemperatuuri) ja kindlatel deformatsioonikiirustel, an exceptionally high strain value shown by some metal alloys and ceramics; the phenomenon is associated with the production of a carefully controlled microstructure consisting of very small, equiaxed grains capable of sliding past each other above a critical temperature at a controlled, defined strain rate; extensions of several hundred percent have been reported