The Influence Of Forging Reduction Onanisotropy Of 7xxx Alloy Extrusion Plate

7xxx aluminum alloy produces the anisotropy in the process of machining, as a kind of high strength aluminum alloy. The mechanical properties at different positions under different reduction( 0% reduction, 50% reduction, 70% reduction, 87.5% reduction) was tested by tensile tests, in order to analyse the anisotropy in the forge plane and the anisotropy in the longitudinal thickness and in the tranverse thickness. The microstructure at different positions after different reduction was analysed by the OM and EBSD. In this methed, we can get the the relationship of the anisotropy of mechanical properties and microstructure.The results of tensile tests on 7xxx aluminum alloy indicated that the anisotropy of mechanical properties reduced at surface thickness and at subsurface thickness of the forge plane with the growth of the amount of reduction. However, the anisotropy of mechanical properties reduce first and then increase slightly at center thickness of the forge plane with the growth of the amount of reduction. In the longitudinal direction, the anisotropy of mechanical properties reduced first and then increased with the growth of the amount of reduction. In the transverse direction, the anisotropy of mechanical properties increased rapidly first and then changed slightly with the growth of the amount of reduction. When the reduction is 87.5%, the anisotropy of mechanical properties of microstructure is the weakest.The results of tensilel tests on 7xxx aluminum alloy indicated that the large size grain along the extrusion direction breaked into small size grain gradually with the growth of the amount of reduction at surface and subsurface of forge plane. When the reduction is over 87.5%, the large size grain was replaced by small equiaxial grain. The long strips large grain was bigger with the growth of the amount of reduction at center of forge plane. When the reduction is 87.5%, the large size grain was replaced by small equiaxial grain. The fraction of recrystallization organization increased with the growth of amount of reduction and the fraction of deformation organization decreases with the growth of amount of reduction in the forge plane. The fraction of recrystallization organization decreased firstly and then increased with the growth of amount of reduction and the fraction of substructure organization increased firstly and then decreased in the longitudinal plane and transverse plane. The texture content decreased with the growth of amount of reduction at the surface and subsurface of forge plane. The texture content decreased firstly and then increased with the growth of amount of reduction at the center of forge plane. The difference of rolling texture between the surface of longitudinal plane and center of longitudinal plane decreased firstly and then increased slightly with the growth of amount of reduction. The difference of shear texture between the surface of taranverse plane and center of tranverse plane rapid increases firstly and then changed slightly with the growth of amount of reduction.The grain morphology, recrystallization organization and texture have some influence on the anisotropy of mechanical properties in the forge plane. The anisotropy of mechanical properties in the different thickness positions of longitudinal plane is influenced by the difference of rolling texture between different thickness positions of longitudinal plane, while the anisotropy of mechanical properties in the different thickness positions of tranverse plane is influenced by the difference of shear texture between different thickness positions of tranverse plane. When the reduction is 87.5%, the texture has little effect on the anisotropy of mechanical properties in the different thickness positions of tranverse plane, while the recrystallization organization has some effect on the anisotropy of mechanical properties in the different thickness positions of tranverse plane.