Influence of Shot Peening on the Surface Hardness of TC11 Titanium Alloy after High Cycle Fatigue Test

摘要

This paper studied the change of surface hardness after high-cycle fatigue(HCF)test of TC11 alloy with and without Shot Peening(WSP). The results showed that the surface hardness gradient of WSP specimens increased after R= -1 and R=0.1 HCF tests. It was found that the depth and magnitude of surface hardness gradient were related to the stress intensity and cyclic times of HCF, which increased with stress intensity; however, the surface hardness gradient of Shot Peening specimens after HCF maintained the same with that before HCF tests, the values of surface hardness varied slightly after HCF. According to analysis, the surface hardness change of WSP TC11 alloy is related to their surface integrity, which, during the cyclic loading, is due to the higher stress concentration generated on the original machining marks and the cyclic softening of surface layer generated by multi-directional stress.