摘要 |
PROBLEM TO BE SOLVED: To provide a method of manufacturing a surface-modified R-Fe-B-based sintered magnet which has superior corrosion resistance and superior surface adhesive properties.SOLUTION: The method of manufacturing a surface-modified R-Fe-B-based sintered magnet includes a process of creating an atmosphere of 1×10to 1×10Pa in oxygen partial pressure, less than 1000 Pa in partial water vapor pressure, and 1 to 20,000 (excluding 1) in ratio of the oxygen partial pressure and the partial water vapor pressure (oxygen partial pressure/partial water vapor pressure) so that a positive pressure state is produced in a processing chamber by introducing an atmosphere gas under conditions of 0.028 m/minute or higher in oxygen flow rate and 3 m/minute or lower in total flow rate for every capacity of 1 min the processing chamber, and subjecting the R-Fe-B-based sintered magnet to a heat treatment at 260-450°C in the processing chamber, the temperature of the magnet being lowered from the temperature at which the heat treatment is performed down to at least 100°C at an average cooling speed of 650°C/hour. |