Experimental study and simulation analysis of thermal-vibratory stress relief treatment of Al-Cu-Mg alloy plate

Abstract

The considerable uneven residual stress (RS) induced by the quenching process of aluminum (Al) alloys causes dimensional instability and deformation. RS relief is essential to enhance the performance of the Al alloys. Thermal vibration stress relief (TVSR), which integrates conventional thermal stress relief (TSR) and vibration stress relief (VSR), has been shown to effectively reduce and homogenize the RS of Al alloys. To date, the detailed processes and mechanisms of TVSR have yet to be studied. Therefore, TVSR experiments considering the coupling rules of TSR and VSR were conducted on the Al-Cu-Mg alloy. Coupled creep-mechanical finite element (FE) models considering the heat preservation time, vibration time, and vibration sequence was devised to predict the residual stress evolution during TVSR treatment. The TVSR simulation results are in good agreement with the experimental results. The results show that TVSR treatment with a heat preservation time of 110 min followed by vibration for 10 min had the optimal stress relief effect, with a stress relief rate 81.7 % higher than that of TSR. Different TVSR processes had little impact on the Vickers hardness and metallographic structure. The TVSR treatment mechanism was also analyzed.