(1. 山东大学 机械工程学院 高效洁净机械制造教育部重点实验室，济南 250061；
2. 中航工业集团成都飞机制造有限责任公司，成都 610092)
摘 要: 针对平均热膨胀系数(CTE)对航空整体结构件热变形准确预测带来较大误差这一问题，利用热机械分析仪在25~500 ℃范围内对7050-T7451铝合金热膨胀系数进行准确测量，采用数值拟合方法获得铝合金7050-T7451热膨胀系数随温度升高的非线性变化规律。从铝合金7050-T7451材料的合金成分和金相结构变化角度，揭示铝合金7050-T7451热膨胀系数变化的材料学内在本质；分别采用平均热膨胀系数和准确热膨胀系数模型对工件变形进行预测分析。结果表明，与平均热膨胀系数模型相比，采用准确热膨胀系数模型时热变形最大相对计算误差由17.4%降为9.5%。
关键字: 7050-T7451铝合金；热膨胀系数；微观结构；热处理；模型误差
（1. Key Laboratory of High Efficiency and Clean Mechanical Manufacture, Ministry of Education,
School of Mechanical Engineering, Shandong University, Ji’nan 250061, China;
2. CAC Chengdu Aircraft Industrial (Group) Co., Ltd., Chengdu 610092, China）
Abstract:Data for the coefficient of thermal expansion (CTE) of pre-stretched 7050-T7451 aluminum alloy are usually given in average values. This may bring a comparatively large error for predicting distortion of aeronautic monolithic components. To solve this problem, accurate measurements of the CTE of 7050-T7451 aluminum alloy were conducted. The measurement was carried out with the help of thermo mechanical analysis (TMA) with temperature varying from 25 to 500 ℃. Numerical fitting method was adopted to obtain the nonlinear variation rules of CTE of the alloy with temperatures. The inherent nature of CTE variation was revealed based on 7050-T7451 composition and metallography. At the end, the deformation prediction analysis of the workpiece was carried out using the average CTE and accurate CTE models, respectively. The results show that the maximum relative error obtained by the accurate CTE drops from 17.4% to 9.5% compared with that of the average CTE.
Key words: 7050-T7451 aluminum alloy; thermal expansion coefficient; microstructure; heat treatment; model error
