The anomalous diffusion processes “dissolution-precipitation” of THE γ′ Phase Ni3Al in AN Fe–Ni–Al alloy during low-temperature deformation

Abstract

An anomalous deformation-induced dissolution of the intermetallics Ni3Al in the matrix of austenitic Fe–Ni–Al alloy has been revealed in experiment at cryogenic temperatures (down to 77K) under high pressure torsion. The observed phenomenon is explained as the result of deformation-stipulated migration of interstitial atoms from a particle into the matrix in the stress field of moving dislocations. With increasing the temperature of deformation, the dissolution is replaced by the deformation-induced precipitation of the intermetallics, which is accelerated due to a sufficient amount of point defects in the matrix, gained as well in the course of deformation at lower temperatures.