Ni-Co-Sn三元系相平衡的实验研究

Experimental Investigation of the Phase Equilibria in the Ni-Co-Sn Ternary System

摘要:

本实验通过采用电子探针显微分析和X-ray衍射分析方法实验研究了Ni-Co-Sn三元体系在700°C和1000°C时的相平衡。在这两个温度截面中均未发现三元化合物。βCo3Sn2相和Ni3Sn2（h）相形成了一个贯穿连续固溶体相。Ni-Sn侧包含Ni3Sn（l）、Ni3Sn（h）和Ni3Sn4三个化合物相，它们中Sn的固溶度是有很大区别的。700°C时，Co在Ni3Sn（l）和Ni3Sn4中的最大固溶度在分别约为6.9 at.%和25.6 at.%，在1000°C时，Co在Ni3Sn（h）中的最大固溶度约为15.5 at.%。在700℃和1000℃下，Ni-Co侧的（αCo，Ni）相为一个贯穿连续固溶体相，并且Sn在（αCo，Ni）相中的固溶度约为1 at.% ~10.5 at.%。Ni在线性化合物CoSn相中的溶解度约为15.9 at.%。

Abstract:

Phase equilibria of the Ni-Co-Sn ternary system at 700 °C and 1000 °C were experimentally determined by using electron probe microanalyzer and X-ray diffraction. No ternary compound was found at 700 °C and 1000 °C. There was an extensive region of mutual solubility existing between βCo3Sn2 phase and Ni3Sn2(h) phase. Three Ni-Sn binary compounds [Ni3Sn(l), Ni3Sn(h) and Ni3Sn4] showed absolutely different solubilities for the element Co. The maximum solubility of Co in Ni3Sn(l) and Ni3Sn4 phases at 700°C were 6.9 at.% and 25.6 at.%, and the solubility of Ni3Sn(h) phases changed into 15.5 at.% at 1000°C. The Ni-Co side presented an interconnected (αCo, Ni) phase region at both 700oC and 1000°C and its homogeneity range for Sn was from 1 at.% to 10.5 at.%. The solubility of Ni in the linear compound CoSn phase was about 15.9 at.%.