基于有限元分析的多腔双层同轴铝合金圆管挤压模具优化

Optimization on extrusion die for multi-cavity double-layer coaxial aluminum alloy circular tube based on finite element analysis

为了减小多腔双层同轴6061铝合金圆管的挤压变形,利用HyperXtrude软件对型材挤压过程进行了数值模拟仿真。根据仿真结果,通过扩大内圆分流腔、增设阻流坎的方法优化了模具结构,将型材出口的最大和最小速度差从19.37 mm·s^(-1)降低至1.37 mm·s^(-1),型材出口速度均方差从8.1 mm·s^(-1)减少至0.31 mm·s^(-1),型材出口速度均匀性大幅提高。然后,通过对比分析得出,优化后模具内金属流动更均匀,挤压载荷和模具应力均有所下降,型材出口温度略有上升,更有利于提高在线淬火后型材的力学性能,优化后模具的所有参数均符合工厂实际挤压生产的要求。最后,在30 MN挤压机上利用优化后的模具结构尺寸和仿真实验的挤压工艺参数生产出合格的产品,证明了基于有限元分析的铝合金多腔双层同轴圆管挤压模具结构优化的可靠性,为多腔双层同轴圆管类型材挤压模具的设计积累了经验。

In order to reduce the extrusion deformation of multi-cavity double-layer coaxial 6061 aluminum alloy circular tube,the numerical simulation on the extrusion process of profile was carried out by software HyperXtrude,and according to the simulation results,the die structure was optimized by expanding the inner circular diversion cavity and adding a flow barrier to reduce the maximum and minimum velocity difference at profile outlet from 19.37 mm·s^(-1) to 1.37 mm·s^(-1) and the standard deviation of profile outlet velocity from 8.1 mm·s^(-1) to 0.31 mm·s^(-1),and improve the velocity uniformity at profile outlet greatly.Then,the comparative analysis shows that the metal flow in the optimized die is more uniform,the extrusion load and the die stress are reduced,and the temperature at profile outlet is slightly increased,which is beneficial to improving the mechanical properties of profile after online quenching.All parameters of the optimized die meet the requirements of the actual extrusion production in the factory.Finally,the qualified product are produced on a 30 MN extruder by using the optimized die structural dimension and simulated extrusion process parameters,which proves the reliability of the optimized die structure for aluminum alloy multi-cavity double-layer coaxial circular tube extrusion based on finite element analysis.Thus,the design experience is provided for the extrusion die design of multi-cavity double-layer coaxial circular tube profiles.