【作者】 包小倩； 李青华； 张茂才； 周寿增；

【Author】 BAO Xiao-qian, LI Qing-hua, ZHANG Mao-cai, ZHOU Shou-zeng(State Key Laboratory for Advanced Metals and Materials, University of Scienceand Technology Beijing, Beijing 100083, China)

【机构】 北京科技大学新金属材料国家重点实验室；

【摘要】 用近快冷凝固技术制备Nd28.6Dy0.5Pr0.5Fe69.2Nb0.2B1.0(简称A合金)、Nd29.0Fe69.1 Ga0.2Nb0.2B1.0(简称B合金)和Nd28.4Dy0.5Fe69.03 Co0.86Zr0.288Nb0.28Al0.125B1.05(简称C合金)鳞片铸锭。鳞片铸锭的显微组织与其厚度有密切关系:厚度为0.20-0.30mm的鳞片铸锭,Nd2Fe14B主相片状晶厚度为3.0-4.0μm,富Nd相薄层均匀分布在片状晶之间,没有a-Fe枝晶的析出;厚度超过0.40mm的A、B鳞片铸锭,容易析出a-Fe枝晶,片状晶厚度增大。鳞片铸锭的显微组织与合金成分也存在密切关系:厚度超过0.40mm的鳞片铸锭,A、B合金中存在较多的a-Fe析出;而在较低稀土含量、同时添加Co、Nb和Zr的C合金中,却未观察到a-Fe析出。X射线衍射分析还表明,鳞片铸锭中Nd2Fe14B相沿<001>裼派ぁ?更多还原

【Abstract】 Microstructure of Nd28.6Dy0.5Pr0.5Fe69.2Nb0.2B1.0 (A) and Nd29.0Pr0.5Fe69.1Ga0.2Nb0.2B1.0 (B) and Nd28.4Dy0.5Fe69.03Co0.86Zr0.288Nb0.28Al0.125B1.05(C) ingots by strip casting has been systematically investigated by SEM. Microstructural characterization of the casts changes with the thickness of strips. Microstructure with fine and homogeneous matrix phase Nd2Fe14B columnar crystals with the size of 3.0-4.0μm and good dispersion of Nd-rich phases between the main phase grains and the absence of a-Fe has been achieved in the A and B ingots with the thickness of 0.20-0.30mm. However, dendritic a-Fe and coarser columnar crystals are observed in the A and B ingots with the thickness in excess of 0.40 mm. Meanwhile, there is a close relationship between microstructure and composition of strips. Dendritic a-Fe is observed in A and B strips with the thickness in excess of 0.40mm, but not in C strips with the addition of Co and Nb and Zr. X-ray diffraction patterns indicate that lamellar Nd2Fe14B phase grows in the preferred orientation of <001>更多还原