The microstructures and mechanical properties of the composite extruded AZ31/AZ31 and AZ31/4047 Al sheets were investigated and made a comparison to the conventional extruded AZ31 sheet.Owing to the introduced intense...The microstructures and mechanical properties of the composite extruded AZ31/AZ31 and AZ31/4047 Al sheets were investigated and made a comparison to the conventional extruded AZ31 sheet.Owing to the introduced intense shear deformation at the interface during the composite extrusion,grain refinement and tilted texture were detected in AZ31 layers of the AZ31/AZ31 and AZ31/4047 Al sheets,while the conventional extruded AZ31 sheet exhibited a relative coarse,inhomogeneous microstructure and strong basal texture.The compressiontension yield ratio was increased gradually from the AZ31 to the AZ31/AZ31 and AZ31/4047 Al sheets.Besides,the AZ31/4047 Al sheet could successfully accomplish the whole bending forming process at room temperature,while the AZ31 and AZ31/AZ31 sheets were both bend-formed to failure with significant cracks in the outer tensile region under the identical bending parameters.Moreover,under the same bending strain,both the outward offset degree of strain neutral layer and the sheet thickening were more serious in the AZ31/4047 Al composite sheet than those of the AZ31 and AZ31/AZ31 sheets.The foremost reason was the quite wide gap of material properties between Mg alloy AZ31 layer(tensile loading in the outer region)and Al 4047 layer(compressive loading in the inner region).展开更多
The texture of a rolled AA3104 aluminum sheet was measured by the X-ray transmission method. The Lankford values or r values （ratio of plastic strain） and yield strengths in directions of 0, 15, 30, 45, 60, 75, and ...The texture of a rolled AA3104 aluminum sheet was measured by the X-ray transmission method. The Lankford values or r values （ratio of plastic strain） and yield strengths in directions of 0, 15, 30, 45, 60, 75, and 90° to RD （rolling direction） of the sheet were tested during tensile loading at a strain of 2%. γ values were predicted by the Sachs model and the reaction stress model in consideration of the measured texture. The simulated results indicate that r values calculated by the Sachs model are more exactly approaching with the experimental values on the whole than those predicted by the reaction stress model. The deformation behavior of the AA3104 aluminum sheet reveals characteristic predicted by the Sachs model, which should be resulted from the sheet geometry different from bulk material as well as the low tensile deformation degree.展开更多
The theory of three-dimensional deformation is used.Based on rigid plastic assumption, the theory of stick friction and the sheet crown curve at the entry and the exit are used. The mathematical analytical formula of ...The theory of three-dimensional deformation is used.Based on rigid plastic assumption, the theory of stick friction and the sheet crown curve at the entry and the exit are used. The mathematical analytical formula of the rolling force in lateral distribution is deriven.展开更多
基金The authors are grateful for the financial supports from the National Key Research and Development Program of China(2016YFB0301104 and 2016YFB0101700)Chongqing Science and Technology Commission(cstc2017zdcy-zdzxX0006,cstc2017jcyjAX0012,cstc2018jcyjAX0472)+3 种基金National Natural Science Foundation of China(51531002 and U1764253)Chongqing Scientific&Technological Talents Program(KJXX2017002)China Postdoctoral Science Foundation(2018T110948)Science and Technology Research Program of Chongqing Municipal Education Commission(KJQN201801306).
文摘The microstructures and mechanical properties of the composite extruded AZ31/AZ31 and AZ31/4047 Al sheets were investigated and made a comparison to the conventional extruded AZ31 sheet.Owing to the introduced intense shear deformation at the interface during the composite extrusion,grain refinement and tilted texture were detected in AZ31 layers of the AZ31/AZ31 and AZ31/4047 Al sheets,while the conventional extruded AZ31 sheet exhibited a relative coarse,inhomogeneous microstructure and strong basal texture.The compressiontension yield ratio was increased gradually from the AZ31 to the AZ31/AZ31 and AZ31/4047 Al sheets.Besides,the AZ31/4047 Al sheet could successfully accomplish the whole bending forming process at room temperature,while the AZ31 and AZ31/AZ31 sheets were both bend-formed to failure with significant cracks in the outer tensile region under the identical bending parameters.Moreover,under the same bending strain,both the outward offset degree of strain neutral layer and the sheet thickening were more serious in the AZ31/4047 Al composite sheet than those of the AZ31 and AZ31/AZ31 sheets.The foremost reason was the quite wide gap of material properties between Mg alloy AZ31 layer(tensile loading in the outer region)and Al 4047 layer(compressive loading in the inner region).
基金This work was financially supported by the National Nature Science Foundation of China (No.50171014) and the National High-Tech Research and Development Program of China (No.2003AA331080)
文摘The texture of a rolled AA3104 aluminum sheet was measured by the X-ray transmission method. The Lankford values or r values （ratio of plastic strain） and yield strengths in directions of 0, 15, 30, 45, 60, 75, and 90° to RD （rolling direction） of the sheet were tested during tensile loading at a strain of 2%. γ values were predicted by the Sachs model and the reaction stress model in consideration of the measured texture. The simulated results indicate that r values calculated by the Sachs model are more exactly approaching with the experimental values on the whole than those predicted by the reaction stress model. The deformation behavior of the AA3104 aluminum sheet reveals characteristic predicted by the Sachs model, which should be resulted from the sheet geometry different from bulk material as well as the low tensile deformation degree.
文摘The theory of three-dimensional deformation is used.Based on rigid plastic assumption, the theory of stick friction and the sheet crown curve at the entry and the exit are used. The mathematical analytical formula of the rolling force in lateral distribution is deriven.
