(1. 重庆大学 材料科学与工程学院，重庆 400044；
2. 重庆大学 国家镁合金材料工程技术研究中心，重庆 400044)
摘 要: 采用DEFORM-3D数值模拟软件对超大规格的宽幅薄壁中空型材进行结构优化；利用HyperXtrude数值模拟软件对该型材的挤压工艺进行优化。型材结构优化后，明显改善速度分布不均匀的现象，规避充填不足、扭拧卷曲的问题；确定出具有一定成形速度及最小速度均方差的优选工艺。在此基础上，成功制备出了光亮平直的超大规格宽幅薄壁中空镁合金型材；该型材截面尺寸为502 mm×60 mm，是目前世界上规格最大的宽幅薄壁中空镁合金型材。对型材各区域进行显微组织观察和力学性能测试，各区域组织均匀细小，平均晶粒尺寸约为10~30 μm，抗拉强度在250 MPa以上，断后伸长率在15%以上。
关键字: 镁合金；宽幅薄壁中空型材；大规格；挤压成形；数值模拟；微观组织；力学性能
（1. College of Materials Science and Engineering, Chongqing University, Chongqing 400044, China;
2. National Engineering Research Center for Magnesium Alloys, Chongqing University, Chongqing 400044, China）
Abstract:The structure of the wide-format thin-walled hollow profile of the large size was optimized by the DEFORM-3D numerical simulation software, and the extrusion process of the profile was optimized by HyperXtrude numerical simulation software. After the optimization of profile structure, the phenomenon of uneven velocity distribution was obviously improved, and the problem of insufficient filling and twisting curl was avoided, and a preferred process with a certain forming speed and minimum average velocity variance was determined. A bright and straight large-size wide-walled hollow magnesium alloy profile was successfully prepared, the profile cross-section size was 502 mm×60 mm, which was currently the world’s largest wide-walled thin-walled hollow magnesium alloy profile. The microstructures observation and mechanical performance testing were carried out on the regions of the profile, the regional tissues are uniform lyson, the average grain size is about 10-30 μm, the tensile strength is above 250 MPa, and the elongation is more than 15%.
Key words: magnesium alloy; wide thin-walled hollow profile; large size; extrusion; numeric simulation; microstructure; mechanical properties
