Creep-fatigue life of Sn-8Zn-3Bi solder under multiaxial loading

This paper describes a creep-fatigue life of Sn-8Zn-3Bi solder under multiaxial loading. A push-pull and a reversed torsion tests were carried out using seven types of strain waveforms, which are a fast-fast, a fast-slow, a slow-fast and a slow-slow waveforms and three types trapezoidal strain waveforms with different strain holding times. The strain waveforms had a significant effect on creep-fatigue life and the shortest creep-fatigue life was found in the slow-fast strain waveform while the longest life in the slow-slow waveform in the push-pull and the reversed torsion tests. Creep-fatigue life in the reversed torsion test was approximately twice longer than that in the push-pull test at each strain waveform. Applicability of common used creep-fatigue damage models for life evaluation was discussed based on the obtained experimental results and only a grain boundary sliding model could evaluate the lives within a small scatter. (C) 2012Elsevier Ltd. All rights reserved.