Host: The Japan Society of Mechanical Engineers
Name : [in Japanese]
Date : December 22, 2018 - December 24, 2018
This paper studies the creep-fatigue life evaluation of Sn-3.0Ag-0.5Cu, Sn-58Bi and Sn-5Sb using miniature specimen under push-pull loading using fast-fast, slow-slow, fast-slow, slow-fast and strain-hold strain waves. Several creep-fatigue data were generated using these strain waves and the effect of strain waveform on the creep-fatigue life of each lead-free solder miniature specimen was discussed. Stress-strain relationship and failure life of Sn-3.0Ag-0.5Cu miniature specimen were compared with those of Sn-3.0Ag-0.5Cu bulk specimen which were quoted from the database of the Japan Society of Material Science. The applicability of two creep-fatigue damage rules, the linear damage rule and the grain boundary sliding model for Sn-3.0Ag-0.5Cu miniature and bulk specimens, was examined. The grain boundary sliding model was originally developed for Sn-37Pb bulk specimen and assumed that the specimen failed when the sum of the grain boundary sliding in each strain wave reached to a critical value. The linear damage rule correlated the creep-fatigue lives of Sn-3.0Ag-0.5Cu miniature and bulk specimens with a large scatter. By contrast, the grain boundary sliding model correlated the lives of both specimens within a factor of 2 scatter band.
