Microstructure control and magnetic property of Nd-Fe-B Sintered magnets after cyclic heat-treatment

Abstract

Nd-Fe-B sintered magnets based on the compound Nd2Fe14B have been widely studied by many researchers as a new type of permanent magnet. In this study, a method of controlling the microstructure which is known to a crucial factor for coercivity was investigated. A cyclic heat treatment was performed repeatedly at certain temperature regions in order to control microstructures such as size and shape of the Nd-rich phase without causing grain growth of Nd2Fe14B phase.