The effect of ultrasonic shot peening on the fatigue life of alloy materials: a review

It is more and more widespread to introduce nano-structured grains on the surface of alloys to improve their strength. One of the technologies to achieve this is the ultrasonic shot peening (USP) technique, which has attracted special attention. With this technology, uniform nano-structured grains can be formed on the surface and compressive residual stress can be developed that can improve the fatigue life. However, pits will be formed during the USP process, which will cause stress concentration and lower the fatigue life. This paper reviews the effects of USP processing parameters on the evolution of the surface morphology, microstructure and residual stress. A finite element simulation based on the velocity model was established to simulate the impact of the USP processing on the fatigue performance.