Formation Mechanism and Control Strategy of Residual Stresses for Quenching 7075 Aluminum Alloy Thick Plate

作者：Qin Guohua^*; Lin Feng; Ye Haichao

来源：Rare Metal Materials and Engineering, 2018, 47(11): 3400-3408.

• 7075 aluminum alloy thick plate
• quenching
• convective heat transfer coefficient
• performance-controlled region
• deformation-controlled region
• residual stress

During the operation of machining process, the release and re-distribution of residual stresses is crucial to machining deformations of aircraft structural parts. Hence, the non-uniform plastic deformations, which are caused by the high temperature gradient field in the quenching process, will give rise to residual stresses. Therefore, a finite element model was established for the quenching process in the present paper. The simulated residual stresses are in good agreement with the experimental data both in the amplitude and in distribution. On this basis, the proposed method was further used to analyze the formation mechanism of residual stress in the quenching of 7075 aluminum alloy thick plate. It is concluded that the final residual stresses have been already determined when the plastic deformations in, the central layer is over at the end slip time. The final residual stresses remain unchanged even if the temperature continues to drop. Finally, the performance-controlled and deformation-controlled method is suggested for residual stresses. Because the deformation-controlled region can strongly impact the final residual stresses whereas the performance-controlled region has a few changes of the final residual stresses, the adjustment of the convective heat transfer coefficient in the deformation-controlled and the performance-controlled region, can accelerate the cooling velocity and reduce the final residual stress.

• 出版日期2018-11
• 单位南昌航空大学; 南京航空航天大学