Optimizing fabrication conditions in pilot scale for sintered Nd-Fe-B magnets

Abstract

In this report, we present the results of study on fabrication teclinology for sintered Nd-Fe-B magnets. Influence of grinding, pressing, sintering and heat treatment processes on magnetic properties of the anisotropic Nd-Fe-B permanent magnets was investigated systematically. By applying wet-pressing technique and two-stage heat treatment process the technology and performance of the magnets can be significantly improved. The optimal technological conditions were found. A low cost, practical applicable technological process has been established to manufacture sintered Nd-Fe-B magnets in pilot scale with their coercivity larger than 7.5 kOe and maximum energy product above 35 MGOe.