Sn-2.5Ag-0.7Cu-XGe钎料显微组织与熔化特性

应用扫描电子显微镜和差式扫描量热仪研究了Sn-2.5Ag-0.7Cu-XGe系三个成分的无铅钎料.结果表明,该合金系的显微组织为鹅卵石状的初晶晶粒加上分散微细条状和小颗粒状的共晶组织.在钎料中添加0.5%或1.0%的Ge元素,显微组织的形貌没有改变,但其中的金属间化合物Ag3Sn和Cu6Sn5趋于细化,分布趋于均匀,Ag3 Sn相从长条状向细小针状转变.加入Ge元素后合金的熔化开始、熔化峰值和熔化结束温度都有所降低.同时Ge元素的加入使熔化曲线的吸热峰宽度变窄,熔化结束部分变长,但对熔化温度区间的影响较小.

Microstructure and melting property of Sn-2.5Ag-0.7Cu-XGe solder

The 3 composition Sn-2.5Ag-0.7Cu-XGe leadfree solders were studied by scanning electron microscope and differential scanning calorimetry equipments.The result indicates that the microstructure is cobblestone-like pro-eutectic grain and scattered long narrow piece and small pellet eutectic mixture.With 0.5% or 1.0% element Ge, the microstructure morphology does not change. But the intermetallic compounds of Ag₃Sn and Cu₆Sn₅ tend to be fine, and their dispersion tends to be well-distributed, and Ag₃Sn phase tends to be fine needle from long narrow piece.By adding element Ge, the temperatures of the melting beginning, the melting peak and the melting finish all reduce correspondingly.And in the melting curve, the endothermic peak changes is narrow, and the melting finish part is long, but the melting temperature zone varies a little.