6005A复杂截面铝合金车体型材挤压过程数值模拟与组织性能研究

Study on numerical simulation,microstructure and properties of aluminum alloy 6005A car body profile with complex section in extrusion process

以复杂截面的6005A铝合金车体挤压型材为研究对象,利用Hyperxtrude有限元软件对挤压过程进行模拟,分析了挤压变形过程中的温度场、速度场及形变场分布。在75 MN挤压机上对铝合金型材进行挤压成形,采用光学显微镜（OM）、扫描电镜（SEM）观察和硬度实验,研究了挤压过程中铝合金型材的组织及性能的变化,并与模拟结果进行了对比。结果表明：由于挤压型材尺寸比较复杂,同一截面上温度、速度和变形量的分布差别较大,对应温度高、速度快及形变量大的部位,其组织细小且第二相数量较多,硬度高;由于型材挤压过程中会产生明显的热效应,导致型材尾部的温度高于型材头部的温度,且型材尾部组织更加均匀,第二相分布更弥散,硬度值更高。

For aluminum alloy 6005 A car body extrusion profile with complex section,the extrusion process was simulated by Hyperxtrude software,and the distributions of temperature field,velocity field and deformation field during the extrusion process were analyzed. Then,the aluminum alloy profile was extruded in the extruding machine of 75 MN,and the microstructures and mechanical properties of aluminum alloy profile were investigated by optical microscopy（ OM）,scanning electron microscopy（ SEM） and hardness test. Furthermore,the microstructures and properties of aluminum alloy profiles during extrusion process were studied,and the simulation results were compared. The results show that for the complex section dimension of extrusion profile,the distributions of temperature,velocity and deformation in the same section are quite different. Corresponding to the position with higher temperature,faster velocity and large deformation,the finer grain with more second phase and higher hardness were obtained. Due to the significant thermal effect during the extrusion process,the temperature of profile tail is higher than that of the profile head,resulting in a more uniform microstructure,more dispersing second phase and higher hardness of aluminum alloy profile tail.