采用放电等离子烧结技术(Spark Plasma Sintering,简称SPS技术)将快淬Nd4.5Fe77B18.5薄带制备成块状纳米晶复合磁体.着重研究了热处理工艺对磁体密度、微观结构和磁性能的影响.结果表明,通过直接烧结得到的磁体具有超细纳米晶结构,合适的热处理可以消除残余非晶,得到较好的晶体结构和磁性能.但过高的热处理温度和较长的保温时间的增大会造成晶粒长大,结果导致磁性能的恶化.在最佳热处理条件下得到的磁体的磁性能为Br=1.014T,JHc=237.21 kA/m,(BH)max=61.85 kJ/m^3.
Melt- spun ribbons of Nd4.5 Fe77 B18.5 alloy were consolidated into bulk permanent magnets by spark plasma sintering(SPS) method. Effect of heat treatment on the density, microstructure and magnetic properties of the magnets were studied. Observation showed that the microstructure of the sample consolidated by SPS directly was consisfed of even nanosize crystal grains. Remnant amorphous phase were removed by proper heat treatment, and fine crystal structure and good magnetic properties were gained consequently. The grain size became larger when the heat treatment temperature and holding time increased. The magnetic properties of magnets under optimum heat treatment were: Br = 1. 014T, JHc = 237.21kA/m, (BH) max =61. 85 kJ/m^3.