| Magnesium alloy is characterized by a number of advantages such as low density, high specific strength and high specific stiffness, but its poor corrosion resistance limits the range of application. Aluminium alloy is characterized by excellent corrosion resistance and plasticity. Covering the magnesium alloy with a layer of aluminum alloy through hot rolling to obtain the5052/AZ31/5052laminated plate can not only play the advantages of magnesium alloy itself, but also improve its corrosion resistance, thus making it more widely used in automobile,3C, aerospace aviation and so on. At present, arduous efforts has been made to the preparation of magnesium-aluminium laminated plate and interfacial microstructure and bonding strength, however, its stamping formability have not been reported. So, this paper mainly studied the deep drawing performance of magnesium-aluminium laminated plate.Firstly, annealing process of AZ31and5052before hot rolling was explored and its influence on the microstructure of AZ31and the mechanical property of AZ31and5052was studied. Besides, the hot rolling process of magnesium-aluminium laminated plate was investigated. The results showed that the optimal comprehensive mechanical properties of AZ31with fine and uniform grain could be obtained in the condition of300℃×30min and air cooling, and its yield strength was175MPa, tensile strength was235MPa and elongation after fracture was16.4%.In the condition of350℃×60min and air cooling, the plasticity of aluminum alloy was improved significantly and its elongation after fracture was26.6%. And before hot rolling, AZ31and5052was annealed as the optimum annealing process, respectively.Secondly, by virtue of microstructure observation and uniaxial tensile tests, the effect of annealing process on the grain size of magnesium alloy matrix and the thickness of interfacial diffusion reaction layer and on the mechanical property was studied. The results showed that the optimum annealing process was180℃×2h and air cooling. After this treatment, the optimal comprehensive mechanical properties of5052/AZ31/5052were obtained:the average grain size of magnesium alloy matrix was minimum (5.64um), the yield ratio was0.635, and the elongation after fracture was17.7%. The thickness of interface reaction layer increased slightly, which increased as the rise of annealing temperature and time. And after hot rolling, magnesium-aluminium laminated plate was annealed as180℃×2h and air cooling.Finally, orthogonal experiments of different forming temperature were conducted to study the impact of punch temperature, drawing speed and die profile radius on the forming property of magnesium-aluminium laminated plate. The results showed that the forming temperature had the most significant effect on limiting drawing ratio. At different temperatures, the effect of a factor on magnesium-aluminium laminated plate was different. The limiting drawing ratio of magnesium-aluminium laminated plate increased as the temperature increased in a certain range, which reached the peak of3.1at200℃and would decrease when the temperature was over200℃.At the optimal forming temperature, the forming property of magnesium-aluminum laminated plate was better than that of magnesium alloy. |
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