Study On Microstructure And Mechanical Properties Of 5052 Aluminum Alloy After Power Spinning

Power spinning is an effective method to produce high-precision and high-performance rotational hollow parts.It has been widely used in the fields of aerospace,military and automobile,etc.In this study,the evolution law of the microstructure and mechanical properties of 5052 aluminum alloy during cold flow forming and shear spinning were investigated respectively.The FEM models of 5052 aluminum alloy fabricated by flow forming and shear spinning were established to learn about the material flow behavior,stress and strain distributions.The purpose of this study is to provide reference for the processing of 5052 aluminum alloy spinning parts with larger size.The results of flow forming show that: the tube,with a diameter of 186 mm and a wall thickness of 6mm,has a single pass thinning limit of 60%,and a multi-pass thinning limit of 90%.The microstructure of the outer layer of the tube wall under low thinning rate is finer than that of the inner layer,and the microstructure becomes uniform when the thinning rate reaches 50%.During the flow forming,low misorientation angles gradually transform into high misorientation angles in initial grains with the increase of the thinning rate,and they finally evolve into high-angle boundaries(HABs)that subdivide the initial grains.The texture transforms from cube and Goss to copper,which results in orientation hardening during the deformation.Under the effect of grain refinement and texture transformation,the yield strength and tensile strength increase respectively from 103 MPa and 225 MPa to 300 MPa and 328 MPa,and the elongation rate reduces from 21% to 5.1%.Simulation results of FEM show that with the thinning rate increases,the gradient of Mises stress,equivalent strain and material flow velocity distribution gradually decrease,and they become uniform when the thinning rate up to 50%.Therefor the uniformity of the microstructure is determined by the stress and material flow.The results of shear spinning show that: the microstructure changes from the initial near equiaxial grains to the uniform fibrous tissue after shear spinning.There is no high-angle boundaries(HABs)in the deformed grains.The yield strength and tensile strength increase from 90 MPa and 210 MPa to 276 MPa and 295 MPa,respectively.Simulation results of FEM show that with the thinning rate increases,the distribution of Mises stress,equivalent strain and material flow velocity are uniform in the direction of the wall thickness after shear spinning,which is beneficial to the formation of uniform tissue in the actual shear spinning process.