晶界添加Ho纳米粉对烧结NdFeB性能的影响

The Influence of Addition of Ho Nanopowder to Grain Boundaries on the Properties of S-NdFeB

为了改善Nd Fe B磁性材料的磁性能和防腐性能,采用双合金法在晶界处添加Ho纳米粉制备高性能永磁材料。对烧结永磁体(PrNd)29.9Dy0.1B1Co1Cu0.15Febal+x Ho(添加Ho纳米粉的质量分数分别为0、0.2%、0.4%、0.6%和0.8%)的形貌、微观结构及成分、磁性能和腐蚀性进行了分析。结果表明,随着Ho元素含量的增加,磁体矫顽力增幅变大;剩磁和最大磁能积降幅渐快,从0.6%到0.8%下降幅度最大。当Ho添加量为0.6%时,综合性能达到最佳。磁体矫顽力达到1108 k A·m^-1,提升了5.8%,剩磁和最大磁能积略微下降,分别为0.3%和0.2%;并且在3.5%NaCl溶液中,添加0.6%Ho纳米粉的钕铁硼磁体,腐蚀电流最小,达到0.327μA·cm^-2,提升了近一个数量级;I(006)/I(105)比值算出,添加量为0.6%Ho时取向度为1.45,磁体密度增加1.6%,达到7.61 g·cm^-3。

The NdFeB magnetic materials were prepared by double alloy method with adding Ho nanopowder to grain boundaries to improve the magnetic property and corrosion-resistant performance.The morphology,phase,magnetic property and corrosion-resistant performance of(PrNd)29.9Dy0.1B1Co1Cu0.15Febal+xHo(x=0,0.2%,0.4%,0.6%and 0.8%,Mass fraction)were analyzed,respectively.The results indicate that the coercive force was enhanced with increase of Ho content,and the remanence and maximum magnetic energy product declined.When content of Ho was from 0.6%to 0.8%,the decline of the remanence and maximum magnetic energy product was the fastest.When adding 0.6%Ho powders,the combination property of samples was the best,the coercive force reached 1108 kA·m^-1,with a increase of 5.8%,and the remanence and maximum magnetic energy product were fell down by 0.3%and 0.2%,respectively.In the 3.5%NaCl solution,the sample with 0.6%Ho powders reached the smallest corrosion current of 0.327μA·cm^-2.And the orientation degree of samples was 1.45 calculated by I(006)/I(105),the magnet density reached to 7.61 g·cm^-3,with a increase of 1.6%.