Patent ID: 7377985
Filing Date: 2008-05-27
Classification: C21D,H01F

Abstract:
1. A temper method for a Nd—Fe—B permanent magnet, comprising (a) heating the magnet in a primary temper process to a primary temper temperature; (b) cooling the magnet in the primary temper process in a cooling liquid in a chamber into which a pressurized cooling exchange gas under a pressure of about 1.8-3.5 times higher than the normal pressure of the cooling gas is introduced; (c) re-heating the magnet in a secondary temper process to a secondary temper temperature; and (d) cooling the magnet in the secondary temper process in a cooling liquid in a chamber into which a pressurized cooling gas under a pressure of about 1.8-3.5 times higher than the normal pressure of the cooling gas is introduced.