固溶时效工艺对6016铝合金力学性能的影响及多目标优化

作为6XXX铝合金热处理工艺的一部分,固溶处理与时效处理对6016铝合金的力学性能有显著影响.本文把固溶温度、时间和时效温度、时间作为设计变量,应用中心组合实验设计法设计固溶-时效实验方案,在室温下分别测出试样的屈服强度、伸长率和维氏硬度.第二代非支配排序遗传算法(NSGA-Ⅱ)解决了第一代算法参数选取难、运行效率低等缺点.本文用第二代非支配排序遗传算法把得到的响应面方程作为目标函数进行多目标优化,经过计算后获得非劣解,从中可筛选出使目标函数较好的解与相对的固溶-时效工艺参数.

Effect of solution and aging processes on the mechanical properties of 6016 aluminum alloy and multi-objective optimization

As a part of heat treatment processes,solution treatment and aging treatment have a great influence on the mechanical properties of 6016 aluminum alloy.In this article,solution temperature,solution time,aging temperature and aging time were taken as parameters to design a heat treatment scheme by central composite design (CCD).At room temperature,the yield strength,elongation,and Vickers hardness of specimens were measured by mechanical testing.The second-generation non-dominated sorting genetic algorithm (NSGA-Ⅱ) solves the shortcomings of the first-generation algorithm,such as the difficulty in parameter selection and low efficiency.In this study,the response surface model derived was used as the objective function to perform the multi-objective optimization by means of NSGA-Ⅱ.After calculation,the Pareto solutions were obtained to filtrate out the solution with comprehensive performance,and then,to acquire the corresponding parameters of the solution and aging process.