AZ31B镁合金板径向推力充液拉深试验

镁合金板冷成形性能差,采用液压成形的方法可提高其冷成形性能。对AZ31B镁合金板进行径向推力充液拉深试验,分析液压力大小、模具尺寸和坯料尺寸对最大拉深高度的影响规律,并对液压拉深件破裂位置、裂纹走向及裂纹形态进行分析。研究结果表明,当凸模圆角半径较大时,随着液压力的增大,得到的最大拉深高度也大;凸模圆角半径较小时,仅有当液压力大小合适时,才能改善其成形性能;板坯直径越大,最大拉深高度就越小。破裂位置一般在拉深试件的底部圆角、凸缘和侧壁处,且裂纹走向、裂纹断面呈现不同的形态。

Experiments of AZ31B magnesium alloy sheets in radial pressure deep drawing

Magnesium alloy sheets have poor formability at room temperature,which can be improved by hydraulic forming.Experiments were conducted to research the deformation behaviors of AZ31B magnesium alloy sheets in radial pressure deep drawing,one of the hydraulic forming technologies.The effects of hydraulic pressure,die dimension,blank size on the limit drawing height(LDH) of the drawn workpieces were investigated,and the location,evolvement and pattern of the fractures were also analyzed.The research results showed that the obtained LDH increased with the hydraulic pressure when the punch corner radius was large enough.While the formability could be improved only under a proper moderate hydraulic pressure when the punch corner radius was small.And the larger the blank size was,the smaller the LDH became.Moreover,fractures appeared on corners,flange and side wall of the drawn workpieces,and showed different evolvement directions and patterns through cross-section.