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通过与计算相图数据库相耦合,建立了Al-Mg-Si三元合金体系中针棒状析出相时效析出动力学和时效强化模型,考虑了析出相形貌对形核、生长、粗化以及强化效果的影响.通过该模型可以获得不同时效工艺下析出相微观组织特征参数的变化及对应的屈服强度变化.利用该模型模拟了Al-Mg-Si合金在不同时效工艺条件下的时效析出过程和屈服强度变化,并与实验结果及Lifshitz-Slyozov-Wanger粗化模型计算结果进行了对比.基于模型研究并分析了析出相长径比、界面能、合金元素含量以及析出相成分对Al-Mg-Si合金时效析出动力学和强化效果的影响.结果表明:不同的界面能和长径比会影响形核密度和析出相尺寸,进而影响合金的屈服强度.增加基体中Mg含量可以促进时效析出,提高合金屈服强度,而基体中Si含量的增加对合金屈服强度并不产生明显影响.
Through the coupling with the database of phase diagram, the aging precipitation kinetics and aging strengthening model of needle bar precipitated phase in Al-Mg-Si ternary alloy system were established. The morphologies of nucleation, growth, coarsening and strengthening were considered The change of the microstructure characteristic parameters and the corresponding change of yield strength under different aging processes can be obtained.The aging precipitation process of Al-Mg-Si alloy under different aging conditions and Yield strength, and compared with the experimental results and the calculated results of the Lifshitz-Slyozov-Wanger coarsening model.According to the model, the ratio of aspect ratio, interfacial energy, alloying element content and precipitated phase composition of Al-Mg- Si alloy.The results show that the different interfacial energy and aspect ratio will affect the density of nucleation and the size of precipitated phase, which will affect the yield strength of alloy.The increase of Mg content in the matrix can promote the aging precipitation, Improve the yield strength of the alloy, and the increase of Si content in the matrix does not have a significant effect on the yield strength of the alloy.