Sn-0.7Cu-2Bi无铅钎料压入蠕变性能的研究
Investigation on Indentation Creep Behavior of Sn-0.7Cu-2Bi Lead-free Solder
廖春丽
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作者单位：（南充职业技术学院 机电工程系，四川 南充 637131）
中文关键字：Sn-0.7Cu-2Bi； 无铅钎料； 压入蠕变
英文关键字：Sn-0.7Cu-2Bi；lead-free solder；indentation creep
中文摘要：采用自制的蠕变装置研究Sn-0.7Cu-2Bi无铅钎料在温度60～120℃、压力30～50 MPa下的压入蠕变性能，利用光学显微镜、SEM和XRD对钎料组织在蠕变前后的变化进行了分析。结果表明：随着温度和应力的增加，钎料的蠕变速率增大；Sn-0.7Cu-2Bi主要由 Sn、Bi、Cu6Sn5三相组成，Bi固溶在Sn中造成晶格的畸变阻碍晶体滑移面的位错运动，导致其变形抗力大为增加，且晶界处偏聚的Bi颗粒对位错有钉扎作用，能提高钎料的抗蠕变性能；Sn-0.7Cu-2Bi钎料蠕变后出现回复再结晶，最终导致晶粒长大。
英文摘要：With self-made apparatus, the indentation creep behavior of Sn-0.7Cu-2Bi lead-free solder was investigated at 60～120℃ under compressive stress of 30～50 MPa, and the change of the microstructure of lead-free solder before and after indentation creep were analyzed by optical microscope, SEM and XRD. The results indicate that the creep rate increases with temperature and compressive stress in creasing, the Sn-0.7Cu-2Bi is composed of Sn,Bi and Cu6Sn5 phases, lattice distortion generated by Bi solid-solving in Sn makes the dislocation movement of crystal siliding surface, which causes the deformation resistance of Sn-0.7Cu-2Bi increasing. Bi on the interfacial boundary serves as a pinning effect on dislocation which enhances the creep resistance of the solder; Sn-0.7Cu-2Bi lead-free solder generates recovery and recrystallization after creep, which results in the grain growth in the end .