通过疲劳裂纹扩展试验研究了TC11钛合金在不同取向及应力比下的疲劳裂纹扩展行为。结果表明：在相同应力强度因子的情况下，随着应力比的增大，TC11钛合金的疲劳裂纹扩展速率增大。通过TC11钛合金的拉伸性能对裂纹扩展门槛值进行估算，得到了可以对TC11钛合金进行全范围疲劳裂纹扩展速率预测的疲劳裂纹扩展模型，为进一步估算其疲劳寿命提供了依据。

The rules of fatigue crack propagation of TC11 titanium alloy under different orientation and stress ratio were researched through the fatigue crack propagation test. The results show that under the same stress intensity factor, the fatigue crack propagation rate of TC11 titanium alloy became higher with the increase of the stress ratio. Through the estimation of the threshold value of crack propagation by tensile properties of TC11 titanium alloy, all range propagation model was obtained, which could evaluate the fatigue crack propagation rate and provide the foundation for predicting the fatigue life of TC11 titanium alloy.