Enhanced mechanical properties in die-upset Nd-Fe-B magnets via die-upsetting process

胡志华¹，瞿海锦²，赵佳奇²，罗成¹，李军³，刘颖³

1. Department of Materials Engineering,Hubei University of Automotive Technology2. Material & Technology Institute,Dongfeng Motor Company Limited3. College of Materials Science and Engineering,Sichuan University

摘 要：The mechanical properties of die-upset Nd-Fe-B magnets produced at different die-upset processes were investigated. The results showed that the optimum comprehensive mechanical properties of die-upset Nd-Fe-B magnets were obtained at the deformation temperature of 680 oC. The anisotropy of Vickers hardness was more obvious at the die-upset level of 55%, and the Vickers hardness measured parallel to the c-axis was significantly lower than that perpendicular to the c-axis. The fracture toughness measured parallel to the c-axis first increased, and then decreased with increase in die-upset level. The maximum fracture toughness of Nd-Fe-B magnets was obtained at the die-upset level of 60%. The microstructure showed that the width of defect layers and the average size of large grains increased, and the layered structure of die-upset Nd-Fe-B magnets was obviously different with increase in the die-upset level.

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