【摘要】 总结了不同金属材料在低周疲劳过程中典型的晶界、孪晶界、相界和微电子互连界面的损伤开裂行为.纯Cu中疲劳裂纹萌生的难易顺序为:小角度晶界、驻留滑移带和大角度晶界.对于纯Cu与铜合金中退火孪晶界,是否萌生疲劳裂纹与合金成分有关,随合金元素的加入降低了层错能,退火孪晶界相对容易萌生疲劳裂纹.对于Cu-Ag二元合金,由于存在不同的晶界和相界面,是否萌生疲劳裂纹取决于界面两侧晶体的取向差,通常两侧取向差大的界面容易萌生疲劳裂纹.在微电子互连界面中,疲劳裂纹萌生位置与焊料成分和时效时间有关,对于Sn-Ag/Cu互连界面,疲劳裂纹通常沿焊料与界面化合物结合处萌生;对于Sn-Bi/Cu互连界面,随时效时间增加会出现明显的由于Bi元素偏聚造成的界面脆性.更多还原

【Abstract】 Interfacial fatigue cracking behaviors along large-angle grain boundaries(GBs),twin boundaries(TBs),phase boundaries(PBs) and joint interfaces in metallic materials were summarized. It is found that the resistance to fatigue crack initiation decreases in the order of low-angle GBs, persistent slip bands and the large-angle GBs in pure Cu.For annealing TBs,fatigue cracking initiation strongly depends on the stacking fault energy(SFE) in Cu alloys.With decreasing SFE,fatigue cracking along TBs becomes easy.In Cu-Ag binary alloys,the misorientation across GBs or PBs plays an important role in the fatigue cracking,and large misorientation often makes the final fatigue cracking.For the Cu/solder joint interface,the interfacial fatigue cracking modes are affected by the solders and aging time.In Sn-Ag/Cu solder joints,fatigue crack normally nucleates along the interface between the Sn-Ag solder and the intermetallics compounds(IMCs);however,for Sn-Bi/Cu solder joints,brittle interfacial fatigue cracking always occurs along the interface between Cu and the IMCs due to the Bi segregation after aging for a long time.更多还原