Stability of Residual Stresses in Ultrasonic Surface Deep Rolling Treated Ti-6Al-4V Alloy under Cyclic Loading
Compressive residual stresses have been found to affect fatigue crack growth behavior by delaying the crack initiation and by decelerating the crack propagation rate. Therefore, various mechanical surface treatment techniques have been developed to produce the compressive residual stresses on the surface of components. However, the residual stresses will relax due to cyclic loading. Hence, the stability of residual stress during fatigue process is a great importance aspect for design of components. In this paper, the ultrasonic surface deep rolling was used to generate the compressive residual stress near the surface of Ti-6Al-4V. The stress relaxation behavior was identified during the low cycle fatigue process. The X-ray diffraction method was used to determine the magnitude and sign of residual stress. Results showed that under cyclic loading, the residual stress relaxation occurred fast in the first few cycles then became stable. Furthermore, it was found that relaxation rates of residual stress were depended on the applied stress.
Prof. Xu Chen and Prof. Shan-Tung Tu
M. D. Mao and X. C. Zhang, "Stability of Residual Stresses in Ultrasonic Surface Deep Rolling Treated Ti-6Al-4V Alloy under Cyclic Loading", Applied Mechanics and Materials, Vol. 853, pp. 173-177, 2017