Rolling Process And Interface Behavior Of Magnesium/Aluminum Explosive Welding Composite Plate

Magnesium alloy has the advantages of light weight,high strength,excellent shock absorption and rich resources,so that it has extensive application prospect.But relative to the poor room temperature forming and corrosion resistance,seriously restrict the expansion of application.Therefore,considering the method of aluminum cladding on the surface of magnesium alloy,can improve the surface properties and performance of magnesium alloy.Combined with the preparation process of magnesium alloy composite materials,the composite plate was prepared by explosive welding and rolling bonding.The composite slabs were prepared by explosive welding,and then obtained the thin magnesium/aluminum composite plates with good comprehensive performance by hot rolling.In the paper,the magnesium/aluminum composite plate was prepared by explosive welding and rolling bonding.The sheet with high surface quality and good performance was obtained by studied the rolling process of the composite plate.Through the study of heat treatment of the composite plate after hot rolling,as to provide the subsequent actual production and sheetmetal forming to provide technical support.In this paper,the AZ31 B / 6061 explosive composite plate with thickness of about 12 mm was successfully prepared by explosive welding process.The interface and structure of the explosive composite panel were observed.The interface of the composite plate was sinusoidal waveform and the adiabatic shear zone which inclined 45 ° along the interface formed on the side of the magnesium alloy.There were a large number of twin organizations at the center of the magnesium alloy.The microhardness results showed that the microhardness of the interface was obviously higher than that of the metal materials on both sides due to the plastic deformation caused by the explosion load.In order to eliminate the work hardening and the adiabatic shear formed on the magnesium alloy by the explosive welding process,the composite plate was subjected to the preheating heat treatment before rolling.The results showed that the heat treatment can effectively eliminate the work hardening caused by the explosion.The adiabatic shear zone disappeared and the micro hardness of the composite plate is reduced and more uniform.The composite plates at 350 ℃ ~400 ℃ for 5 min before hot rolling,can eliminate the hardening phenomenon after explosion and the grain size was uniform and can avoid the interface diffusion layer thickness so large that reduced the interface bonding strength and had adverse impact on subsequent rolling.The composite plate was subjected to different degree of warping and edge crack after the first pass rolling with different reduction ratio.When the reduction ratio was 30%,the composite plate was relatively straight and the coordination deformation was better.With the increase of the reduction rate,the degree of recrystallization of the magnesium alloy side increased,the grain refinement,and the tensile strength of the compositeplate gradually increased,the maximum can reach 300 MPa.The ABAQUS finite element was used to simulate the first rolling of the composite plate.The simulation results of the rolling process of the composite plate showed that the simulation results were in good agreement with the experiment result,which can predict the producing conditions of edge crack of the composite plate during the rolling process and provide some guidance on the actual rolling.The composite plate heated at 400 ℃ by 5 pass,each pass at 30%reduction rate and heat treatment at 400 ℃,5min before the rolling,the thickness of magnesium/aluminum composite plate was 2.14 mm after rolling,composite interface with no cracks and edge crack,and the surface quality is good.Under different annealing conditions,the diffusion layer at the interface was different,and the increase of the diffusion layer thickness is not obvious at low temperature.With the annealing temperature increasing,the thickness of the diffusion layer increased rapidly,and the thickness of diffusion layer was 100μm at 400℃、2h.The composite plate has good mechanical properties after rolling,the tensile strength and elongation of the composite plate at the heat treatment condition of 200 ℃、2h were 285 MPa and 24.5% respectively.When the heat treatment temperature increased,the mechanical properties of the composite plate was decreasing due to the presence of intermetallic compound layer.