Experimental Study And Constitutive Modeling On The Anisotropy Of AA 6061 Aluminum Alloy

AA 6061 aluminum alloy is a high-quality aluminum alloy produced by heat treatment and pre drawing process.It has a very broad development prospect in aerospace,shipbuilding,automobile manufacturing and other fields.However,AA 6061 aluminum alloy sheet has obvious anisotropic mechanical behavior,which often causes springback,wrinkling,fracture,thinning and other problems in the forming process.Therefore,it has important theoretical significance and engineering application value to study anisotropic mechanical behavior in different directions of AA 6061 aluminum alloy.By means of tensile and compression test,secondary loading test,optical microscope and XRD,the texture distribution,tensile properties and fracture toughness of the plate under different loading conditions were analyzed.The reason of anisotropy was explained.Based on VPSC,the secondary loading process is simulated,and the anisotropic behavior of aluminum alloy is explained from the start of slip system.The main work includes:(1)The tensile strength and fracture toughness of AA 6061 aluminum alloy are different in different directions,The microstructure after fracture was observed and it was found that the strengthening phase was Mg2 Si.The anisotropy of the strength and fracture toughness of the plate due to the presence of coarse second phase particles.(2)After compression of 6%,8% and 10% in the direction of RD,ID and TD,small samples were cut and uniaxially stretched.The results show that with the increase of compression degree,the cube texture gradually increases,and some cube textures begin to rotate in the direction of TD and RD,forming the cube-td and cube-rd texture.(3)The anisotropic behavior of AA 6061 aluminum alloy under different pre compression conditions is simulated by VPSC model.The results show that sliding is the main deformation mechanism after the aluminum alloy enters the plastic deformation stage under the action of tensile stress.