超大规格宽幅薄壁中空镁合金型材挤压成形的数值模拟及实验研究

The DEFORM - 3D numerical simulation software is used to optimize the structure of the super - large wide - width thin - walled hollow profile; the HyperXtrude numerical simulation software is utilized to optimize the extrusion process of this profile. After the profile structure is optimized, the phenomenon of uneven velocity distribution is significantly improved, and the problems of insufficient filling, twisting and curling are avoided; the preferred process with a certain forming speed and the minimum velocity mean square deviation is determined. On this basis, a super - large wide - width thin - walled hollow magnesium alloy profile that is bright and straight has been successfully prepared; the cross - sectional dimension of this profile is 502 mm×60 mm, which is the largest wide - width thin - walled hollow magnesium alloy profile in the world at present. The microstructure of each area of the profile is observed and the mechanical properties are tested. The microstructure in each area is uniform and fine, with an average grain size of about 10 - 30 μm, a tensile strength of more than 250 MPa, and an elongation after fracture of more than 15%.

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。