Residual stress distribution and elevated temperature fatigue behaviour of laser peened Ti-6Al-4V with a curved surface

The influence of laser shock peening without coating (LPwC) on the induced compressive residual stress and the fatigue behaviour (R = -1 at 300 degrees C) was investigated on curved samples of Ti-6Al-4V. The stress relaxation after fatigue was also examined. In the peened samples crack initiation shifted to a depth of ~ 200 mu m, with 3 fold increase in fatigue life at 400 MPa. Decrease in fatigue striations in the laser peened (331.48 nm/cycle) samples compared to unpeened (410.54 nm/cycle) samples indicated retardation of crack propagation rate. Further, the effect of grain refinement and misorientation angles on fatigue behaviour is also considered.

Automated summary

The influence of laser shock peening without coating (LPwC) on the induced compressive residual stress and the fatigue behavior of curved samples of Ti-6Al-4V was investigated. The study found that laser shock peening can increase fatigue life and retard crack propagation rate. The effect of grain refinement and misorientation angles on fatigue behavior was also considered.