Enhanced magnetic properties in Nd-Fe-B magnets prepared by spark plasma sintering via die-upsetting process

• Published in: Journal of rare earths Vol. 29; no. 7; pp. 660 - 663
• Main Author: 胡志华 储林华 李军 刘颖
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.07.2011; Department of Materials Engineering, Hubei University of Automotive Technology, Shiyan 442002, China%College of Materials Science and Engineering, Sichuan University, Chengdu 610064, China
• Subjects: Alignment; deformation temperature; Ferrous alloys; Grains; Magnetic materials; Magnetic properties; Magnets; Microstructure; Nd-Fe-B magnets; Rare earth metals; rare earths; spark plasma sintering; the die-upset level; 微观结构; 放电等离子烧结; 火花等离子烧结; 磁体; 磁学性质; 镦粗; magnetic properties; the die-upset level; deformation temperature; spark plasma sintering; Nd-Fe-B magnets; rare earths
• ISSN: 1002-0721; 2509-4963
• DOI: 10.1016/S1002-0721(10)60517-0

The magnetic properties and microstructure of Nd-Fe-B magnets prepared by spark plasma sintering with different die-upsetting processes were investigated. The results showed that the optimum magnetic properties of die-upset Nd-Fe-B magnets were obtained at 680 ℃ when the die-upset level was 60%, and the degree of magnetic alignment was 0.84. The microstructures showed that the coarse grains oc-curred predominantly within certain areas, and abnormal grain growth was not observed within the major areas of well-aligned grains. There existed many small spherical grains, which stacked together and were not aligned during die upsetting when the deformation temperature was 650 ℃. These small spherical grains grew up, and were aligned when the deformation temperature increased from 650 to 680 ℃, which could improve the crystallographic alignment of die-upset Nd-Fe-B magnets.