Effect of vibratory stress relief on fatigue life of aluminum alloy 7075-T651

Vibratory stress relief is a green and efficient aging technology compared with traditional natural stress relief and thermal stress relief. The research aimed to determine whether vibratory stress relief is feasible to improve the fatigue life of aluminum alloy 7075-T651 or not. Under the same resonance frequency, analyses and comparisons of the residual stress distributions before and after vibratory stress relief are presented with X-ray method. Experimental results indicate that vibratory stress relief is effective in reducing and equilibrating residual stresses. Through uniaxial tension-compression fatigue tests, we obtained the S-N curves for specimens under states of original and varying exciting forces. Findings led to the conclusion that vibratory stress relief can improve the fatigue life of aluminum alloy 7075-T651 when dynamic stress does not exceed 8% of the yield strength.