7050铝合金残余应力冷变形消减工艺仿真研究

Simulation study on reducing residual stress of 7050 aluminum alloy by cold de formation process

实测了7050铝合金热物性参数得到了高温应力-应变曲线及淬火过程温度变化曲线,构建了7050铝合金热处理和冷变形工艺仿真模型,分析了7050铝合金试块固溶淬火、冷压过程的应力变化。结果表明:残余应力累积主要产生在固溶淬火阶段,淬火后残余应力为外压内拉状态。随着淬火温度的降低,试块心部拉应力有所提高。单向压缩后,心部的三向拉应力可转变为三向压应力状态。卸载对冷变形的效果有明显影响。综合考虑,3%左右的预变形量可以保证卸载后仍然保持有效的应力消减效果。

The si mulation model of the heat treatment and cold deformation process of 7050 aluminum alloy was built,and the stress changes of the samples made by 7050 aluminum alloy during the quenching and cold pressing process were analyzed based on the measured thermal physical parameters,high temperature stress-strain curves and temperature variation curves during quenching.The results show that the residual stress mainly accumulates during the solid solution quenching stage,and the residual stress after quenching is in the state of external compression and internal tension.The tensile stress at the core of sample increases with the decrease of quenching temperature.Triaxial tensile stress state in the centre of uniaxial compression sample may change to triaxial compressive stress state.Unloading has obvious influence on reducing residual stress by cold deformation process.In general,the deformation of about 3%can ensure the effective residual stress reduction after unloading.