HDDR处理过程中NdFeB粉末的相分解显微组织及磁各向异性

Decomposed Microstructures During the HDDR Process and the Magnetic Anisotropies of NdFeB-Type HDDR Powder

利用装有场发射电子枪的高分辩扫描电子显微镜 (FE- SEM)和透射电子显微镜 (TEM) ,研究了 Nd12 .6Fe余 Co17.4B7.0 Zr0 .1Ga0 .3 合金在 HDDR处理过程中氢化相变分解后的混合显微组织。发现其显微组织是一种在 α- (Fe,Co)基体上分布着纤维状的 Nd H2 和球状的 Nd H2 相构成的组织。纤维状 Nd H2相的体积百分比和 α- (Fe,Co)的尺寸随 (HD)处理温度的提高而增加。同时当氢化相变分解 (HD)温度升高时 ,(Fe,Co) 2 B相消失转而形成新相 (TE相 )。在 HDDR处理过程中氢化相变分解后添加一段 Ar气氛下的等温处理 (IA处理 )可使 HDDR粉末的磁各向异性得到改善 ,其显微组织中纤维状 Nd H2 相的体积百分数减少 ,而 α- (Fe,Co)晶粒尺寸增加 ,伴随着 (Fe,Co) 2 B消失。这些现象表明氢化相变分解后组织结构中 α- (Fe,Co)晶粒尺寸的增大有利于

Decomposed microstructures in Nd 12.6 Fe余Co 17.4 B 7.0 Zr 0.1 Ga 0.3 alloy after the hydrogenation decomposition(HD) stage of the hydrogenation decomposition desorption recombination(HDDR) process were investigated by field emission scanning electron microscopy(FE SEM) and transmission electron microscopy(TEM).It was found that the decomposed microstructures consist of regions of fibrous NdH 2 and spherical NdH 2 in the matrix of α (Fe,Co).The volume fraction of the fibrous NdH 2 regions and the size of α (Fe,Co) increased with the treatment temperature in the HD stage. It was also found that disappearance of (Fe,Co) 2B and formation of a new phase(TE phase) occur when the HD temperature is raised.