基于蠕变时效交互作用机理的2219铝合金统一本构建模

发布时间：2018-04-18 15:00

本文选题：铝合金 + 蠕变时效　；参考：《中南大学学报(自然科学版)》2017年11期

【摘要】：在不同的时效温度和试验应力条件下,对2219铝合金开展蠕变时效行为研究。随后,分别对蠕变试样进行力学性能测试和透射电镜观察,以获得该合金在蠕变时效过程中的力学性能演变规律和析出相演变规律;进一步查明材料蠕变量、析出相特征尺寸与力学性能的关系。在此基础上,建立基于成形成性耦合作用机理的2219铝合金蠕变时效本构方程,采用粒子群算法(POS)对方程中的材料常数进行拟合,并将蠕变应变和屈服强度的拟合结果与试验结果进行对比。研究结果表明:试验应力、时效温度和时效时间都会对2219铝合金的蠕变行为产生重要影响;通过提高试验应力或时效温度,可以缩短蠕变第二阶段的时间,加速蠕变第三阶段(蠕变破坏阶段)的到来。蠕变应变和屈服强度的拟合结果的相对误差分别为2.70%和0.70%。基于成形成性耦合作用机理的铝合金蠕变时效统一本构方程能够较好地反映蠕变与时效形性演变规律。
[Abstract]:Creep aging behavior of 2219 aluminum alloy was studied under different aging temperature and test stress.Then, the mechanical properties of the creep specimen were tested and the TEM observation was carried out to obtain the evolution law of mechanical properties and precipitation phase of the alloy during creep aging, and to find out the amount of creep of the alloy.The relationship between the characteristic size of precipitated phase and mechanical properties.On this basis, the constitutive equation of 2219 aluminum alloy creep aging based on formative coupling mechanism is established, and the material constants in the equation are fitted by particle swarm optimization (PSO).The fitting results of creep strain and yield strength are compared with the experimental results.The results show that the creep behavior of 2219 aluminum alloy can be greatly affected by the experimental stress, aging temperature and aging time, and the time of the second stage of creep can be shortened by increasing the test stress or aging temperature.The arrival of the third stage of accelerated creep (creep failure phase).The relative errors of the fitting results of creep strain and yield strength are 2.70% and 0.70% respectively.The unified constitutive equation of creep aging of aluminum alloy based on formative coupling mechanism can better reflect the evolution of creep and aging.
【作者单位】：中南大学高性能复杂制造国家重点实验室;中南大学机电工程学院;
【基金】：国家重点基础研究发展计划(973计划)项目(2014CB046602) 国家自然科学基金资助项目(51235010) 国防科工局重大项目课题(JCKY2014203A001)~~
【分类号】：TG146.21

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