Effects of process parameters on residual stress and compressive layer depth during ultrasonic surface rolling of AA6061 alloy

Tóm tắt

This study investigates the influence of process parameters in the Ultrasonic Surface Rolling Process (USRP), including static force Fs, vibration amplitude A₀, ultrasonic frequency f, and rolling ball radius R₁, on the distribution of compressive residual stress and the depth of the compressive layer in AA6061 aluminum alloy. Based on Hertzian contact mechanics combined with an elastic–plastic mapping rule, an analytical model is developed to establish the relationship between process parameters and the characteristic outputs of the surface-hardened layer formed during USRP. The model predictions are validated through comparison with previously published experimental data. The results indicate that, within the investigated range, static force Fs has the strongest influence on both the magnitude of compressive residual stress and the depth of the compressive layer. The rolling ball radius R₁  mainly affects stress propagation into the subsurface region, whereas the vibration amplitude A₀ and ultrasonic frequency f exhibit smaller effects.