Al-7Si-Mg铝合金拉伸过程应变硬化行为及力学性能模拟研究

发布时间：2018-01-20 20:30

本文关键词： Al-Si-Mg铝合金拉伸性能应变硬化析出相时效处理模拟　出处：《金属学报》2017年09期 　论文类型：期刊论文

【摘要】：建立了时效析出动力学模型、强化模型以及应变硬化模型,针对Al-7Si-Mg合金开展拉伸性能模拟研究。时效析出动力学模型可以模拟析出相密度、尺寸、分布、体积分数、基体中元素含量等微观组织参数,并结合强化模型获得合金的屈服强度。通过应变硬化模型可模拟合金在拉伸过程的应力-应变曲线,并结合关系式(σ_(UTS)-σ_Y)=m·σ_Y+n+f(T_(ss))获得合金的抗拉强度和延伸率。本工作首先模拟了Al-7Si-0.4Mg合金的析出相特征参数及屈服强度并进行实验验证,分析了模拟结果与实验结果之间存在偏差的可能原因。采用应变硬化模型模拟了Al-7Si-0.36Mg合金在拉伸过程的应力-应变曲线,分析时效处理和铸态组织细化程度对位错存储速率、动态回复速率及合金的应力-应变曲线的影响规律。采用本模型预测了Al-7Si-0.4Mg合金在不同时效温度下的抗拉强度和延伸率,并与实验结果进行对比,分析了二次枝晶臂间距对拉伸性能的影响。最后,对模型存在的局限性及影响拉伸性能预测精度的因素进行了分析。
[Abstract]:The aging precipitation kinetics model, strengthening model and strain hardening model are established. The tensile properties of Al-7Si-Mg alloy are simulated. The aging precipitation kinetic model can simulate the precipitation phase density. The microstructure parameters, such as size, distribution, volume fraction and element content in matrix, were used to obtain the yield strength of the alloy. The stress-strain curve of the alloy in the tensile process could be simulated by the strain hardening model. And combined with the relational formula (蟽-蟽 Yam 路蟽 Y n ft / T / T / n). The tensile strength and elongation of the alloy were obtained. The characteristic parameters of precipitate phase and yield strength of Al-7Si-0.4Mg alloy were simulated and verified by experiments. The possible reasons for the deviation between the simulation results and the experimental results were analyzed. The stress-strain curves of Al-7Si-0.36Mg alloy during tensile process were simulated by strain hardening model. The effect of aging treatment and as-cast structure refinement on the dislocation storage rate was analyzed. The influence of dynamic recovery rate and stress-strain curve of Al-7Si-0.4Mg alloy was studied. The tensile strength and elongation of Al-7Si-0.4Mg alloy at different aging temperature were predicted by this model. Compared with the experimental results, the influence of secondary dendritic arm spacing on tensile properties is analyzed. Finally, the limitations of the model and the factors affecting the precision of tensile properties prediction are analyzed.
【作者单位】：清华大学材料学院先进成形制造教育部重点实验室;明志科技有限公司;
【基金】：国家重点基础研究发展计划项目No.2011CB706801 国家自然科学基金项目Nos.51374137和51171089~~
【分类号】：TG146.21
【正文快照】： the ultimate tensile strengths and elongations can be obtained by combining this model with the experi-mental data fitted with the expression(sUTS-sY)=m·sY+n+f(Tss).First,the evolution of precipitate microstruc-ture parameters and yield strengths as a f

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