High Coercivity in Ultra-Fine Grained PrFeBCu Alloy Prepared by Torsion Deformation

Abstract

The alloys of the R-Fe-B system (R is a rare earth element) are of great scientific and practical interest. In a ultra fine-grained (UFG) state the given alloys are the most power-intensive hard magnetic materials for permanent magnets [1]. However, the potentialities of methods of powder metallurgy, hot deformation and rapid quenching used for production of R-Fe-B magnets have already been exhausted Therefore, intense attempts aimed to develop new methods of production of R-Fe-B magnets with high hysteretic properties are made. One of these directions is severe plastic deformation (SPD). In recent years a number of works have been published about the influence of UFG structure produced by SPD on some physical properties of metals and alloys including magnetic materials [2,3]. The use of SPD, in particular torsion straining under pressure, for processing of high coercive R-Fe-B alloys seems very promising.