银基钎料中铈与杂质元素铅、铋作用机制

Mechanism of Interaction Relation between Rare Earth Element Cerium and Impurity Elements Lead and Bismuth in Ag-Based Filler Metal

研究了银基钎料中铈与铅、铋的作用机制 ,发现在银基钎料中铈与铅、铋易形成高熔点的CePb ,CeBi化合物 ,从而抑制了铅单质相和铋单质相的形成 ,消除了杂质元素铅、铋对银基钎料铺展性能的有害作用。金属学分析和量子力学成键理论分析结果表明铈与铅、铋有极强的化学亲和力 。

The mechanism of interaction between rare earth element Ce and Pb or Bi in Ag-based filler metal was studied. The results show that the compounds CePb and CeBi with high melting point can be easily produced between these three elements in the filler metal, which eliminates the formation of the Pb or Bi single substance phase and reduces removes the negative effect of impurity elements Pb and Bi on spreading property of the Ag-based filler metal. The bond formation analysis shows that a strong chemical affinity to form CePb or CeBi existes between rare earth element Ce and Pb or Bi, which was proved by the XRD analysis.