Study on strengthening and toughening of sintered rare-earth permanent magnets

A scanning electron microscope is used for studying the fracture behavior and micromechanism of the experimental magnets and the impact stability of rare-earth permanent magnets (REPM) is examined by using a falling-weight impact tester and an impact-acceleration standard device based on laser interference method. The impact stability has increased from 2.5*[10.sup.4] g for the ordinary magnet specimens to 11*[10.sup.4]g for the strengthened and roughened specimens and it is shown that Ti-doping has decreased the Vickers-hardness [H.sub.v].