Numerical Simulation Of Rolling Process And Experimental Research On Al/Mg/Al Laminate With Large Thickness Ratio

Al/Mg/Al laminate has the advantages of corrosion resistance and high specific strength,and is widely used in parts and shells of aircraft and automobiles.In the existing research on Al/Mg/Al laminates,the thickness ratios of magnesium and aluminum are mostly below 10,and the proportion of aluminum reaches about 20%,which increases the overall density.In order to meet the needs of light-weight anti-corrosion for satellite structural parts in the aerospace field,the thickness ratio of magnesium and aluminum has been increased to reduce weight and increase specific strength.The reduction ratio is an important factor that affects the performance of the laminate after rolling,and there are few studies on the reduction ratio and rolling simulation of Al/Mg/Al laminate with large thickness ratio.In order to study the effect of reduction ratio on the performance of Al/Mg/Al laminates with large thickness ratio,this paper studies from both experimental and simulation aspects.In the rolling experiment,a 0.2 mm thick 1060 aluminum strip and a 5 mm thick AZ31B magnesium alloy plate were used.The thickness ratio of magnesium and aluminum was 25.The hot rolling experiment of holding at 400? for 10 min was carried out using five reduction ratios of 33%,41%,49%,60%and 66%.At different reduction ratios,the rolled laminate is flat and straight.When the reduction ratio is 49%or less,no edge cracking occurs.The microstructure performance analysis shows that in the line scan results of the interface of Al/Mg/Al laminate,no obvious intermetallic compound platform appeared.Initial bonding was achieved at 33%reduction rate;there was a micro defect in the bonding interface at 41%reduction rate;good bonding is achieved at 49%and above reduction,and the interface does not separate after tensile fracture.When the reduction ratio is 41%,the bending strength is the largest.When the reduction ratio is 49%,the grains are equiaxed,the average grain size is 2.87?m,and the elongation is the largest(26%).Relative to the elongation of Al/Mg/Al laminates in the current research,it has been greatly improved.When the reduction ratio is 60%,the maximum tensile strength is 315MPa due to the occurrence of shear bands.In order to study the variation and distribution of stress and strain,metal flow and temperature of the laminate during the rolling process,the finite element software Marc was used for simulation analysis.A temperature-force coupled two-dimensional Al/Mg/Al laminate rolling simulation model was established,and the thickness of the aluminum layer after simulation and experiment was compared.In this paper,the Y-direction,rolling normal stress,shear stress,contact friction stress,total equivalent strain and temperature field of Al/Mg/Al laminate are extracted and analyzed.The results show that with the increase of the reduction rate,the stress and strain of the Al/Mg/Al laminate gradually increase,which promotes the bonding of the Al/Mg/Al laminate interface.The amount of reduction has little effect on the position of the neutral point.As the reduction rate increases,the outlet temperature gradually decreases due to the lengthening of the rolling deformation zone,resulting in the generation of edge cracks and grain refinement at the reduction rates of 60%and 66%.When the reduction ratio is 49%,the strain of the Al/Mg/Al laminate is uniform,resulting in equiaxed and uniform grains,and the elongation is significantly improved.The non-uniformity of strain makes the tensile strength of Al/Mg/Al laminate is the largest and the elongation is the smallest when the reduction ratio is 60%.In the aluminum layer,the temperature and the thickness have a linear function.In the magnesium layer,the temperature and the thickness have a quadratic function.The thermal effect of metal deformation is obviously increased in the region where the magnesium alloy has a large equivalent strain.When the reduction ratio is 49%,the Al/Mg/Al laminate with large thickness has less edge cracks,good interface bonding,fine and uniform grains,good tensile and bending resistance properties,significantly improved elongation,and the best overall performance...