Effect of surface treatments on fatigue life of Ti-6-22-22 alloy at room and high temperatures

Shot-peening and ion implantation were adopted to treat the surface of machined specimens of Ti-6-22-22 alloy, then stress-controlled fatigue tests were performed at room temperature and 400 °C. Experimental results indicate that the effects of shot-peening and ion implantation on the S–N curves are dependent on temperature. For Ti-6-22-22 alloy fatigued at room temperature, the effects of both, shot-peening and ion implantation of carbon ions on fatigue strength at high cyclic lives are slight. At 400 °C, the fatigue strength at high cyclic lives is obviously increased for both, shot-peening and ion implantation of carbon ions in comparison with the untreated counterparts.