| 摘要 |
PURPOSE:To obtain a good R-Fe-B sintered magnet by conducting heat treatment effectively by a method wherein a sintered body is heat-treated at 400 to 700 deg.C in an atmosphere containing 1vol% or more of oxygen. CONSTITUTION:An R-Fe-B alloy ingot is pulverized to make alloy powder. R is one or more kinds out of La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu and Y. The alloy powder is made into a desired shape in a magnetic field and the compact is sintered in inactive gas. The sintered body is heat-treated to make an R-Fe-B sintered magnet. At that time, the heat treatment is conducted at 400 to 700 deg.C in an atmosphere containing 1vol% or more of oxygen. Then, an oxygen diffusion layer is formed on the surface of the R-Fe-B sintered magnet and it prevents oxididation from moving into of the magnet. By this, a good R-Fe-B sintered magnet can be obtained. |
