Effects of Sintering on the Magnetic and Mechanical Properties of Nd-Fe-B Permanent Magnetic Materials

Nd33Dy1.5FebalAl0.4B1.02 sintered magnets were prepared from 4μm alloy powder and sintered at 1353K for different times. Effects of sintering on the magnetic and mechanical properties of magnets were analyzed. As the sintering time was extended from 0.25h up to 24h, the intrinsic coercivity and bending strength of materials initially increased considerably and then decreased relatively slowly, and the remanence and hardness first increased substantially and then continued to rise at a slow rate. Both high relative density and small average grain size attained by the choice of reasonable sintering processing parameters are believed to be a practical and effective technical measure to improve the magnetic and mechanical properties of sintered Nd-Fe-B permanent magnet materials.