Microstructure And Properties Of Mg-Al Clad Sheets During Symmetric/Asymmetric Rolling

Metal composite has the characteristics with complementary component properties which fulfill the requirements working under complex working environment. On the surface of magnesium alloy by rolling composite covered with a layer of aluminum or aluminum alloy, which can retain the magnesium alloy material strength, high specific stiffness, good anti-corrosion properties, electromagnetic shielding performance, many of the characteristics of good dimensional stability, and can play aluminum oxidation, corrosion resistance, impact resistance the advantages of good performance. This study is mainly focused on how to improve the efficiency of rolling and bonding strength of the composite plate to develop an optimal production process of Mg-Al composite plate.This subject respectively in different material thickness ratio, different rolling temperature, different rolling methods were successfully combined with magnesium composite plate good preparation, and studied the effect of processing parameters on the composite board. For the Mg-Al composite plates after rolling were annealed in different annealing process, determined the best, discussed with the internal layer and diffusion layer material.The results show that:(1) It is achieved reduce the bonding reduction rate to 30% for Mg-Al Composite when the roller is heated up to 270℃. If the industrial pure aluminum plate thickness is 0.5mm, the bonding strength of Mg-Al composite plate increasing with the increase of the thickness of raw material of magnesium alloy decreases gradually.(2) Asymmetric rolling method can effectively reduce the rolling force, the rate under the same pressure, the average decline of up to 10%. Due to the existence of shear stress in rolling zone during asymmetric rolling, deformation of composite interface is more severe, magnesium composite plate prepared has relatively better performance.(3) The bonding strength of Mg-Al composite plate with the rolling temperature increased first and then decreased, at 350℃, combined with the peak intensity. So the choice of 350℃ under asymmetric rolling is the best rolling process. The yield strength of rolling process for magnesium composite plate prepared by up to 153 MPa, tensile strength 230 MPa, has the best mechanical properties.(4) The annealing temperature is 350℃, the annealing time for 60 min can promote the composite plate produce intermetallic compound Mg17Al12 in binding layer and produce Mg2Al3 in diffusion layer. The best proportion can improve the bonding properties of the composite plate. The annealing process can also release the residual stress inside the material. And the matrix material of magnesium alloy grain uniformity, thus improving the overall plasticity of the composite plate.