Study On The Deep Drawing Of Mg/Al Bimetal Laminated Sheet

Magnesium alloys, light weight metallic strutural materials has specific stiffness, specific strength and electromagnetic shielding properties, and their sheets has a great application potential. Due to its poor corrosion resistance, the wide application of alloy is limited. However, aluminum alloy has high corrosion resistance and plastic forming performance. Covering the magnesium alloy sheet with aluminum alloy sheet, we can obtain the Mg/Al bimetal laminated sheet which is a new type of metal structural materials. 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. The Mg/Al bimetal laminated sheet will be widely applied to the fields of aerospace, automobile and electronic industry.Scholars in the domestic and overseas only study the forming of bimetal laminated sheet and its interfacial behavior. The bimetal laminated sheet’s formability has not been studied yet. Sheet metal production usually include deep drawing process which is one of the important way of sheet metal forming, so the deep drawing process of Mg/Al bimetal laminated sheet was studied by the experimentally.In this paper,1060aluminum alloy sheets were heat treated at different conditions. The temperature of heat treatment was between320℃and440℃, the holding time was between1h and3h, the cooling methods were air cooling. Erichsen tests was used to study the effects of heat treatment parameters on the properties of1060aluminum alloy sheets. The best annealing treatment is done on the condition of temperature of400癈and holding time of2h. Experiments were conducted to investigate layer stacking sequence, the effects of thickness of layers and forming temperature on the deep drawing process of AZ31magnesium/1060aluminum alloy laminated sheets under the temperature range of100℃～270℃by self-made warm deep drawing die. The thickness of each layer for the drawn component was measured and the thickness distribution in each layer was analyzed. Therefore, the effects of several parameters on the deep drawing process of laminated sheets are comprehensively studied to promote the further development of the Mg/Al bimetal laminated sheet. This study is of great significance and is conducive to the promotion of magnesium alloy sheet products application.Following conclusions were obtained from the research:The results showed that the bimetal laminated sheet exhibits better deep drawability when the magnesium layer is in contact with the drawing punch. When Mg/Al bimetal laminated sheet was drawing, with the increase in the thickness of metal members, the maximum drawing force increases, and the magnesium sheets of great tensile strength have more impact on the maximum drawing force of laminates. Considering the thickness distributions of Mg/Al bimetal laminated sheets drawn cup, the deep-drawing property of this kind of sheet is better when the thickness ratio of magnesium layer to aluminum layer is1:1. It was demonstrated that the LDR of Mg/Al bimetal laminated sheet were added with the increase of drawing temperature, then a declining curve after reaching to a certain degree. When the optimum drawing temperature is200℃, the LDR of Mg/Al bimetal laminated sheet is2.4. The risk fracture position for a drawn cup of laminated sheet was also at the punch profile radius similar to that of monolithic sheet.