中文摘要：

采用纳米压入法对Sn3.0Ag0.5Cu无铅焊点金属间化合物（IMCs）Cu_3Sn和Cu_6Sn_5进行测试,对其不同压入应变率下（P/P＆=0.01,0.05,0.25,0.5 s-（-1））的力学性能进行研究。结果发现金属间化合物具有应变率敏感性,Cu3Sn和Cu6Sn5加载曲线的锯齿流变不同,表明两者在弹-塑性转变过程中的位错成核与增殖程度不同;不同应变率下Cu_3Sn和Cu_6Sn_5的接触刚度均与压入深度呈线性关系且Cu_3Sn的弹性模量和硬度明显高于Cu_6Sn_5,随着应变率的增大二者的硬度值均增大而弹性模量则基本不变。加载应变率较高时保载段的蠕变位移较大,以应变率为0.05 s-（-1）时的蠕变数据为研究对象,Cu、Cu_3Sn、Cu_6Sn_5和Sn3.0Ag0.5Cu焊料的蠕变应变率敏感指数m分别为0.0163,0.0117,0.0184和0.0661。

英文摘要：

The intermetallic compounds（IMCs） Cu_3Sn and Cu_6Sn_5, which were generated in Sn3.0Ag0.5Cu lead-free solder, were characterized using nanoindentation under different strain rates of 0.01, 0.05, 0.25 and 0.5 s~（-1）. The effect of strain rate on mechanical properties was studied. Mechanical responses of Cu_6Sn_5 and Cu_3Sn show great dependence on the strain rate during loading. In addition, multiple pop-in events are observed in Cu_6Sn_5 but not evident in Cu_3Sn. During loading, the contact stiffness of IMCs increases almost linearly with the indentation depth under each strain rate. On the whole, the hardness and elastic modulus of Cu_3Sn are larger than those of Cu_6Sn_5, and the hardness of both Cu_6Sn_5 and Cu_3Sn increase with the strain rate increasing. During the holding stage, creep deformations of IMCs increase as loading strain rate increases. The creep strain rate sensitivity index m of Cu, Cu_3Sn, Cu_6Sn_5 and Sn3.0Ag0.5Cu solder are 0.0163, 0.0117, 0.0184 and 0.0661, respectively, when the loading strain rate is 0.05 s（-1）.