Ni元素含量对BiSbSnxNi钎料润湿性能和抗剪强度影响

研制开发高温无铅软钎料一直是钎焊领域一大难题.熔点为270℃左右的Bi5Sb8Sn钎料因润湿性能和抗剪强度达不到要求而受到限制.通过在Bi5Sb8Sn中添加不同含量Ni元素形成新型BiSbSnNi四元合金,来改善Bi5Sb8Sn合金的润湿性能和力学性能.结果表明,尽管Ni元素的添加使BiSbSnxNi钎料合金铺展面积均较基体钎料差.但Ni元素的最佳添加量为2%时,可以改善钎料中金属间化合物的生成,能够增大钎料的铺展面积.当Ni元素含量为3%时,钎料合金的抗剪强度最高.在Ni元素含量为4%时,IMC厚度明显增加,且出现条状的富铋相,对钎料焊接接头的抗剪强度产生不利影响.

Effect of content of Ni on wettability and shear strength of BiSbSnNi solder alloy

It is one of difficult problems to research and develop the high temperature lead-free soft solder in the brazing field. Bi5Sb8 Sn solder with the melting point of around 270℃ islimited because its wettability and shear strength could not meet the requirements. A new BiSbSnNi quaternary alloy was prepared by adding different content of Ni in Bi5Sb8 Sn to improve the wettability and mechanical properties of Bi5Sb8 Sn alloy. Results show that adding Ni makes Bi5Sb8 Sn solder alloy spreadability worse than that of matrix solder. However, when the content of Ni is 2%, both the solder intermetallic compounds formation and the spreading area can increase. When the Ni content is 3%, the shear strength of the Bi5Sb8Sn3 Ni alloy reaches the maximum. When the Ni content is 4%, the IMC thickness increases significantly and a lot of strip Bi phase emerges, which has an adverse effect on the shear strength of the soldered joint..