中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 36 No. 3 March 2026 |
（a Key Laboratory of Advanced Functional Materials, Ministry of Education, College of Materials Science and Engineering, Beijing University of Technology, Beijing 100124, China;
b School of Mechanical and Aerospace Manufacturing Engineering, Anyang Institute of Technology, Anyang 455000, China;
c State Key Laboratory of Materials Low-Carbon Recycling, Beijing University of Technology, Beijing 100124, China）
Abstract:To improve the overall magnetic properties of Sm(CoFeCuZr)z sintered magnets, a dual-alloy sintering process that involves mixing high-iron, low-copper powders with low-iron, high-copper powders was systematically investigated. The results demonstrate that this method significantly improves the Cu-lean phenomenon at the grain boundaries, achieves multiscale uniform microstructures, greatly enhances the pinning field strength, and ultimately produces a high-performance dual-alloy magnet with a maximum energy product ((BH)max) exceeding 240 kJ/m3 and an intrinsic coercivity (Hcj) exceeding 2400 kA/m. In particular, when 35 wt.% of low-iron, high-copper alloy powder is incorporated, the dual-alloy magnet achieves a remanence of 1.13 T, Hcj of 2691.2 kA/m and (BH)max of 248 kJ/m3. To evaluate the overall magnetic performance, the sum of Hcj (in kA/m) and (BH)max (in kJ/m3) is used as a combined parameter, yielding a value of 2939.2. Compared with single-alloy magnets of the same composition, the dual-alloy sintering process yields magnets with a more uniform elemental distribution and superior magnetic properties.
Key words: Sm(CoFeCuZr)z magnets; dual-alloy sintering process; magnetic properties; coercivity mechanism; magnetisation reversal process
