【作者】 陈瑞； 许庆彦； 郭会廷； 夏志远； 吴勤芳； 柳百成；

【Author】 CHEN Rui;XU Qing-yan;GUO Hui-ting;XIA Zhi-yuan;WU Qin-fang;LIU Bai-cheng;Key Laboratory for Advanced Materials Processing Technology,Ministry of Education,School of Materials Science and Engineering,Tsinghua University;Suzhou Mingzhi Technology Co.Limited;

【机构】 清华大学材料学院先进成形制造教育部重点实验室； 苏州明志科技有限公司；

【摘要】 屈服强度、抗拉强度和延伸率是Al-7Si-Mg铝合金铸件常用的力学性能评判指标,因此建立相应的定量化模型进行拉伸力学性能的预测具有重要工程应用价值。本文建立了时效析出动力学、屈服强度、应变硬化模型,模拟Al-7Si-Mg合金在拉伸过程的应力-应变曲线和相应的拉伸力学性能。针对Al-7Si-0.4Mg合金,开展相应的实验研究,获得不同时效工艺下的拉伸应力-应变曲线以及力学性能数据,归纳出σ_UTS-σ_Y与σ_Y之间的关系式。模拟了该合金在180℃时效条件下屈服强度、抗拉强度和延伸率随时效时间的变化并进行实验结果对比,同时分析了时效工艺对合金应变硬化的影响规律。更多还原

【Abstract】 The tensile properties including yield strength,ultimate tensile strength and elongation are commonly used to judge the mechanical properties of casting in Al-7 Si-Mg alloys,thus establishing the quantitative models to predict the tensile properties plays an important role in the engineering application.The present paper presents the precipitation kinetics model,yield strength model and strain hardening model in order to predict the stress-strain curve and further the tensile properties in Al-7 Si-Mg alloys.Corresponding experiment was carried out for Al-7 Si-0.4 Mg alloy to acquire the stress-strain curves and the tensile properties after aged for different times,and further generalized the linear relationship between σ_UTSσ_Y and σ_Y for the under-aged and peak-aged samples.Using these models,the yield strength as a function of aging time at 180℃ was predicted and compared with the experimental results.The influence of precipitate microstructure parameters on yield strength was analyzed.Using the strain hardening model,the stress-strain curve after yield strength is calculated and is also compared with the experimental measured ones.Through combining the calculated stress-strain curve with the relationship between σ_UTS-σ_Y and σ_Y,the ultimate tensile strength and elongation is also predicted and compared with experimental values.更多还原