镁/铝合金双金属叠层板的拉深性能

摘要

镁/铝合金双金属叠层板兼具镁合金与铝合金两种金属材料的优势，可用于生产同时具有良好耐腐蚀性、轻量化及减震性的产品。而钣金件的生产通常都包括拉深成形，因此首先采用 DYNAFORM 软件模拟镁/铝双金属叠层板的拉深过程，模拟结果表明，镁板与拉深凸模接触时，镁/铝双金属叠层板的拉深性能较好。利用自制的温热拉深模具对不同厚度AZ31镁合金/1060铝合金双金属叠层板在100~270℃温度范围内进行拉深实验，研究板坯厚度、成形温度等因素对镁/铝双金属叠层板拉深性能的影响，并分析拉深后得到的筒形件的壁厚分布。结果表明，拉深过程中的最大拉深力随着叠层板板厚的增加、板坯成形温度的降低而增大；双金属叠层板拉裂的危险区域与单金属板拉深一样出现在凸模圆角处。与镁合金、铝合金单层板拉深相比，镁/铝双金属叠层板拉深使筒形件的凸耳减小。%The Mg/Al bimetal laminated sheet combines advantages of both magnesium alloy and aluminum alloy materials, and can be used to produce lightweight products of good corrosion resistance and vibration damping property. Sheet metal production usually includes deep drawing process, so the deep drawing process of Mg/Al bimetal laminated sheet was simulated with DYNAFORM softwave. The simulation results show that the bimetal laminated sheet exhibits better deep drawability when the magnesium layer is in contact with the drawing punch. The experiments were conducted to investigate the effects of layer thickness and forming temperature on the deep drawing process of AZ31 magnesium/1060 aluminum alloy laminated sheets in the temperature range of 100-270℃. The thickness of each layer for the drawn component was measured and the thickness distribution in each layer was analyzed. It is demonstrated that the maximum drawing force increases with the increase of the thickness of laminated sheets and the decrease of the forming temperature, and the risk fracture position for a drawn cup of laminated sheet is also at the punch profile radius similar to that of monolithic sheet. In addition, the deep drawing of Mg/Al alloy laminated sheets may reduce the earring height compared with the drawing of magnesium alloy or aluminum alloy sheet.