Quenching Residual Stress Evolution And Machining Distortion Of 2024 Aluminum Alloy Blan

The developement of monolithic component production is strongly required in the field of aerospace industry. During the machining process of the monolithic component, the removement of the raw material leads to a release of residual stress(RS) of the blank, which then leads to distortion, then restrict the fabrication of components. Therefore, to investigate the evolution of the RS all through fabrication process is necessary for the distortion control. In this study, the finite element analysis combined with the experimental measurement was used to investigate the residual stress ecolution of 2024 aluminum alloyThe simulation cobined with the experimental indicate that, the quenching induced residual stress(QIRS) is caused by inhomogeneous deformation in different regions of blank. Secondly, the QIRS distributes symmetrically along the thickness of the 2024 alloy plate, of which the surface stress is tensile stress and the core stress is compressive stress. Additionally, with the quenching temperature decreases, the quenching residual stress of the 2024 alloy sheet increases significantly. The manxium residual stress respectively is 200 MPa, 140 MPa, 75 MPa and 2MPa, when the temperature of quenching is 20℃, 60℃,80℃ and 100℃. The numerical simulation results are in good agreement with the experimental measurements with around 10% deviation at the largest.The simulation of the cold compression process showes that both integral compression and partition compression can reduce the QIRS significantly. The residual stress still distributes symmetrically along the thickness direction in the integral cold compressed plate. The maxmium RS is below 70 MPa all through the plate, and the RS reduction is approximately 70%. However, strongly strain and distortion happen on the surface of the partially compressed plate. In case of I-shaped components, the compression ratio and cold compression modes have an obviously effect on the RS and distortion. It is identified that the most efficient way to reduce the QIRS is to compresse the component surface uniformly by the mold with 1% compressive ratio. Through the mode, the residual stress reduction percent is about 50%.The simulation and experimental result of the machining process indicates that the residual stress of blank sheet and the machining modes have an obviously effect on the residual stress release and distortion. The distortion can be smaller with the lower blank residual stress and the symmetrically reliease of residual stress. When the residual stress reliease symmetrically, the distortion of plate and component ares repretively 0.01 and 0.12 mm, while the distorition are 0.6 and 0.45 mm when the symmetrically reliease of residual stress.Furthermore, the finite element simulation and experimental results of residual stress are in great agreement, which indicates that the model of machining processs in this study is reasonable.