Study On Hot Rolling Technology And Properties Of Al-Mg-Al Composite Plate

Magnesium alloy is one of the most potential light alloys at this stage.It has the advantages of high strength,low density and good process performance.It is widely used in aviation,transportation,automobile,electronics and other fields.However,the disadvantages of poor corrosion resistance of magnesium alloy seriously restrict the development and application of its advantages.Aluminum alloy,which is second only to steel,has excellent corrosion resistance,ductility and toughness.Therefore,the 6061 aluminum alloy plate is coated on both sides of AZ31 B magnesium alloy plate by the way of coating aluminum alloy with magnesium alloy.The 6061/AZ31B/6061 symmetrical composite plate can effectively make up for the shortcomings of magnesium alloy easy to corrosion and improve the mechanical properties of magnesium alloy layer.It can be seen that aluminum magnesium composite plate is a kind of material with wide application prospect.In this paper,based on the theoretical calculation and finite element simulation,the 6061/AZ31B/6061 three-layer composite plate was prepared by hot rolling method,and the influence of rolling and annealing process parameters on the comprehensive mechanical properties,interface microstructure,interface bonding strength and microstructure of magnesium alloy composite plate was studied.First,on the basis of the classical composite plate theory,the formulas for calculating the stiffness and strength of the 6061/AZ31B/6061 magnesium alloy composite plate and the 6061 aluminum alloy composite plate were derived.Analysis and calculation of 6061/AZ31B/6061 composite panels under different rate of aluminum alloy cladding performance indicators,including: tensile stiffness,bending stiffness,tensile strength,bending strength and safety coefficient and other indexes,determine the composite board has the best mechanical properties of aluminum alloy layer cladding rate,selection for finite element simulation and the experiment of rolling thickness than to provide a theoretical basis.Secondly,on the basis of the optimal aluminum alloy coating rate,deform-3d finite element software was used to simulate and analyze the hot rolling process of 6061/AZ31B/6061 three-layer composite plate.The temperature field,stress field and strain field in the hot rolling process are obtained,and the effects of different rolling processes on the bonding performance of composite plate are analyzed.Then,the optimal aluminum alloy coating rate calculated by the theory was used to form the billet,and within the range of the optimal rolling down rate obtained by the simulation calculation,the hot rolling experiment of 6061/ AZ31B/6061 three-layer composite plate was carried out on the two-high experimental mill of Shanxi key laboratory of metallurgical equipment design theory and technology.Composite plates with different rolling temperature,different reduction rate and different annealing time were prepared.Finally,the mechanical properties,microstructure,microstructure and residual stress of the prepared 6061/AZ31B/6061 composite plate were tested.The effects of different rolling and annealing process parameters on the mechanical properties of the composite plate,the thickness of interfacial diffusion layer,the microstructure of magnesium alloy and the residual stress were analyzed,and some guidance Suggestions were given for the actual production of the three-layer composite plate 6061/AZ31B/6061.