Sn-Bi-In低温无铅钎料的组织和性能研究

Microstructures and Properties of Sn-Bi-In Low-temperature Lead-free Solders

摘要:

研究了Sn-Bi-In钎料的微观组织、热学特性、润湿性能以及力学性能随合金成分的变化特点。结果表明：Sn-Bi-In钎料的显微组织含有β-Sn相、Bi相以及InBi中间相,Bi含量的减少会导致Bi相和InBi相所占比例降低；钎料DSC曲线中存在三个不同大小的吸热峰,所有合金熔化开始温度在101.3-103.4℃之间,随着Sn含量的增加,钎料的熔程先减小后增大,铺展面积先增大后减小；钎料的显微硬度随着Bi含量的增加而增大,且In的添加使钎料的硬度明显高于Sn-Bi共晶合金；钎料的抗拉强度和断后伸长率随着Bi含量的增大而降低。

Abstract:

The characteristics of microstructures, thermal properties, wettabilities and mechanical properties of Sn-Bi-In solders with different content were studied. The results show that the microstructure of Sn-Bi-In solders consists of β-Sn, Bi and InBi phases, the reduction of Bi content can result in the proportion decrease of Bi and InBi phases. There are three endothermic peaks with different magnitudes on the DSC curves, and the onset melting temperature of solders are around 101.3-103.4℃, with the increase of Sn concentration, the melting range of solders firstly decreases and then increases, while the spreading area firstly increases and then decreases. The mircrohardness of solders increases with the rising of Bi conetent, in addition, the hardness is remarkably higher than Sn-Bi eutectic alloy when the In element is added to solder. The tensile strength and elongation of solders decrease with reduction of Bi content.