【摘要】 在悬浮熔炼装置上采用玻璃包熔的净化处理工艺,可使Nd—Fe—B—Si合金熔体获得凝固前的深过冷,实验结果表明:随着过冷度的增加,枝晶形态由树枝晶向胞晶转变,并且是突发性的;该合金获得最大无量纲过冷度θ≥0.3。用X射线衍射分析表明;在深过冷Nd—Fe—B—Si合金的凝固组织中存在着亚稳相。更多还原

【Abstract】 By means of a technique of glass encasement on a levitation melting assembly high undercoolings of melt before solidification were obtained for the Nd - Fe - B - Si systems. It is odserved that a transition of growth form from dendritic to cellular occurs as the undercooling is getting higher, and it is a sudden transition, The highest dimensionless undercooling (θ=AT/TL) obtained for the system excesses 0. 3, and X-ray diffraction analysis shows the existence of a metastable phese in the so-liditied microstructure in this case.更多还原