放电等离子烧结Fe3B／（Pr,Tb）2Fe14B块体纳米晶双相复合永磁体的性能

Properties of Fe3B/(Pr,Tb)2Fe14B Bulk Nanocomposite Magnets Prepared by Spark Plasma Sintering

摘要:

采用放电等离子烧结技术将非晶Pr4.2Tb0.3Fe78B17.5薄带制备成块状纳米晶复合磁体。研究了烧结条件对磁体密度、微观结构和磁性能的影响。结果表明，烧结温度的升高可使磁体得到高致密度，但同时由于其晶粒长大，结果导致磁性能的恶化。在最佳烧结条件下得到磁体的磁性能为Br=1．02T，JHc=220kA／m。磁体具有较好的微观结构，平均晶粒尺寸为20nm。

Abstract:

Amorphous melt-spun ribbons of Pr4.2Tb0.3Fe78B17.5 alloy were consolidated into bulk nanocomposite magnets by Spark Plasma Sintering method. Effect of sintering conditions on the density, microstructure and magnetic properties were studied. Higher sintering temperature improved the densification of the magnets, while deteriorated their magnetic properties simultaneously due to the excess crystal grain growth. Magnet possessed a Br of 1.04 T and a JHc of 220 kA/m under the optimal sintering condition, and its microstructure contained satisfied grains with an average size of about 20 nm.