Rare earth permanent magnets prepared by hot deformation process
Chen Ren-Jie1, †, Wang Ze-Xuan1, Tang Xu1, Yin Wen-Zong1, Jin Chao-Xiang1, Ju Jin-Yun1, Lee Don2, Yan A-Ru1, ‡
       

Images of the different shapes of punches and the ring magnets prepared with them: (a) half-spherical-end punch; (b) arc-shaped-end punch; (c) beveling cylinder; (d) cylinder.[6]