TC21钛合金室温高周疲劳寿命表征

High Cycle Fatigue Life Representation of TC21 Alloy at Room Temperature

通过试验得到应力集中系数为1,3,5和应力比为-1,0.06,0.5对应的TC21钛合金的S-N曲线,讨论应力集中系数和应力比对TC18钛合金高周疲劳性能的影响。结果表明:应力比或应力集中系数的升高都会使疲劳强度降低;运用Zheng公式对试验数据进行分析,得到各条件下疲劳寿命曲线;采用Zheng公式当量名义应力幅S eq处理试验数据,发现当Kt=1时,拟合效果不佳。通过修正,得到适用于TC21合金疲劳寿命预测新模型,为工程化应用提供依据。

The fatigue properties of TC21 alloy was discussed while a serials of S-N curves with stress concentration factor for 1, 3 and 5 and stress R-ratios for -1, 0.06 and 0.5 were tested. The results show that the increase of the stress ratio and the stress concentration factor can make fatigue strength decrease; the fatigue life curve was given by using Zheng formula. Zheng formular can not best fit the experiment data when Kt=1 ,and a new model which is suitable for pedicting the fatigue life of TC21 alloy was obtained and a reference for the engineering application was provided.