再次喷丸周期对TC18钛合金疲劳寿命的影响

Effect of Re-shot-peening on the Fatigue Life of TC18 Titanium Alloy

研究了再次喷丸对于经过预先喷丸的TC18钛合金残余应力和室温疲劳寿命的影响。使用X射线衍射仪和旋转弯曲疲劳机测定了再次喷丸后的合金的表面残余应力以及总疲劳寿命。结果表明,疲劳试验会使预先喷丸的TC18钛合金疲劳试样表面残余压应力松弛30%～50%,而再次喷丸可以使由于疲劳而松弛的表面残余压应力回复到疲劳试验前试样的50%～70%。此外,相比未经过再次喷丸的试样,选择合适的再次喷丸周期可使TC18钛合金的总疲劳服役寿命提高了75%。

The effect of re-shot-peening treatment on the residual stress and room temperature fatigue life of initially shot-peened TC18 titanium alloy was investigated.The change of surface residual stress and fatigue life after re-shot-peening were examed by X-ray diffraction and rotating-bending fatigue tester,respectively.The results show that the surface residual stress relaxed in the range of 30%-50% because of pre-fatigue test,and that re-shot-peening successfully recovered the relaxed surface residual compressive stress up to the 50%-70% of the original.Further,compared with the samples excluding re-shot-peening,fatigue life of TC18 titanium alloy can be increased by 75% when re-shot-peened after the suitable pre-fatigue cycle.