Rejuvenation of Deformation-Damaged Material by Magnetic Annealing - A New Approach to Grain Boundary Engineering -

Abstract

A new approach to grain boundary engineering has been extended to unsolved engineering materials problem, that is “rejuvenation of damaged materials”. The application of a high magnetic field during annealing of deformed ferromagnetic iron cobalt alloy was found to enhance the elimination of intergranular cavities introduced by high temperature deformation and the restoration of the density. Relative density decreased slowly with increasing plastic strain up to certain level then rapidly decreased leading to the final fracture. The formation and interlinkage of intergranular cavities are very likely controlled by the grain boundary character distribution (GBCD) and the grain boundary connectivity. Intergranular cavities are mostly associated with random boundaries. It was also found that the degree of rejuvenation increased with increasing the magnetic field strength and annealing time.