材料期刊网

运用基于AZ31镁合金本构方程与ALE算法的HyperXtrude软件对典型AZ31薄壁管材的挤压过程进行数值模拟,并通过调整焊合室高度、焊合室大圆角及焊合室坡度3个结构参数,分析不同条件下应力分布与速率分布的变化情况.结果表明:焊合室内近工作带处压力随焊合室高度增加不断减小,分流孔与焊合室压力的最大值与平均值均随焊合室大圆角增大发生降低,分流孔与焊合室压力随焊合室入口坡度增大不断增大,并在焊合室高度为16mm、大圆角为18mm以及入口坡度为15°时金属流速均方差达到最小值.优化模具结构缓解了应力集中与流速不均等问题,在实验生产中得到合格产品,型材组织均匀细化.

The extrusion process of typical AZ31 magnesium alloy tube was simulated by using the constitutive model of AZ31 alloys and ALE-based HyperXtrude software.The changes of stress distribution and velocity distribution were analyzed under different conditions, through the adjustment of three structural parameters, including the height, big round corner and gradient of weld chamber.The results show that the pressure near the work zone in the weld chamber decrease with the increase of the height of weld chamber, the maximum value and average value of the pressure in the weld chamber are decreasing with the increase of big round corner of weld chamber, and the pressure in the port holes and weld chamber increases with the increase of the gradient of weld chamber.The minimum variance of metal flow rate is achieved in the height of weld chamber with 16mm, big round corner with 18mm and gradient of weld chamber with 15°.The optimized structure alleviates the issues of stress concentration and non-homogeneous flowing velocity.The final die is proved to be capable of producing the qualified products and the microstructure after extrusion is uniform and fine.