7050铝合金结构件热处理与冷成形过程残余应力演化规律的数值模拟  

Modeling of residual stress evolution of 7050 aluminium alloy component during heat treatment and cold forming

作　　者：王浩 肖纳敏 李惠曲 王晓 WANG Hao;XIAO Na-min;LI Hui-qu;WANG Xiao(AECC Beijing Institute of Aeronautical Materials,Beijing 100095,China)

机构地区：[1]中国航发北京航空材料研究院,北京100095

出　　处：《材料工程》2021年第8期72-80,共9页Journal of Materials Engineering

摘　　要：基于Hansel-Spittel黏塑性流变应力模型以及应力-应变曲线构建7050铝合金在不同温度区间的材料本构方程。采用有限元仿真技术,首先分析试块级试样淬火与冷压缩过程的残余应力变化,模拟的分布规律与试块的超声测试分析结果一致。在此基础上,研究带筋条结构的铝合金结构件淬火热处理与冷变形工艺残余应力演化规律,并对结构件开展了超声残余应力测试和机加工变形验证。结果表明:淬火后残余应力呈外压内拉分布。不同的冷变形工艺对结构件淬火残余应力的消减程度有较大差异。对于冷压缩工艺,当变形量超过2%后,辐板压缩对辐板心部的应力状态改善较好,而筋条压缩只改善筋条局部位置的应力状态。3%压下量的冷拉伸工艺对整体的应力状态改变较大,可同时有效改善筋条部位和辐板部位残余应力的均匀性。经冷拉后,铝合金结构件机加工变形程度可得到明显改善。A thermal mechanical coupling numerical model of 7050 aluminium alloy was established using the Hansel-Spittel constitutive model.The stress state of the samples during quenching and cold deformation was analyzed using the finite element simulation technology at first,which is in good accordance with the measured result by ultrasonic test.Then,residual stress evolution rule during heat treatment and cold deformation of an aluminium component with rib structure was studied and ultrasonic residual stress inspection and matching deformation verification were carried out on the structural component.The results show that residual stress after quenching is in the state of external compression and internal tension.The reduction degree of quenching induced residual stress by different cold deformation methods is obviously different.For cold compression,when deformation exceeds 2%,compression on the web obviously improves stress state of the whole web region while compression on the lib has relatively less improvement.For cold stretching,3%deformation can effectively improve the stress uniformity for both web region and lib region.After cold stretching,the distortion during machining can be obviously improved.

关 键 词：7050铝合金 残余应力 冷变形 热力耦合模拟 

分 类 号：TG166.3[金属学及工艺—热处理]