Abstract: Aiming at the problem of planar warping distortion of a G-type lid made of ZL101A alloy after heat treatment, numerical simulation method was used to predict the easy-distorted part of the lid, and then anti-distortion measures were conducted. Firstly, a multi field coupling model of temperature-heat transfer-stress and strain was established, the thermal physical parameters such as the specific heat capacity and thermal conductivity of ZL101A alloy was calculated by JMatPro software, and the heat transfer coefficient of water and AQ260 aqueous solution were tested. Based on these, the influence of furnace loading method and quenching medium on the quenching distortion of the G-type lid was simulated using ANSYS finite element method, meanwhile a series of experiments were conducted by combining the simulation results. The simulation results show that the distortion of the lid treated by hanging+PAG aqueous solution quenching is the smallest, with a planar warping distortion value of 3.5603 mm. Considering that there is a distortion of about 1 mm in the as-cast state lid, which cannot meet the machining requirement of ≤4 mm in actual production, a scheme of enhancing structural rigidity is adopted to control the lid distortion. The experiments results show that the methods of point welding stiffeners or attaching stiffeners can both reduce the planar warping distortion during the heat treatment of the lid, and the scheme of hanging+PAG aqueous solution quenching+attaching stiffeners achieves the best distortion control, with the planar warping distortion of all three tested lids ≤2.5 mm, meeting the machining requirements.

Key words: ZL101A aluminum alloy, lid, numerical simulation, heat treatment distortion, furnace loading method, quenching medium, structure rigidity