Hot deformation behavior and microstructural evolution of as-homogenized 7A65 Al alloy under isothermal compression at temperatures of 573-713 K and strain rates of 0.1-10.0 s-1were investigated.It was found that the ...Hot deformation behavior and microstructural evolution of as-homogenized 7A65 Al alloy under isothermal compression at temperatures of 573-713 K and strain rates of 0.1-10.0 s-1were investigated.It was found that the flow stress of 7A65 Al alloy exhibited a typical dynamic recovery characteristic at high-temperature deformation conditions,and a sixth-order polynomial strain compensated Arrhenius constitutive equation was proposed to describe the flow behavior.Based on the dynamic material model and the Prasad standard,the hot processing map was established.The optimal processing conditions were within the temperature range of 633-713 K and the strain rate range of 0.1-0.5 s^(-1)when the true strain exceeded 0.6.Deformation temperature and strain rate had an obvious effect on the micros tructure evolution of 7A65Al alloy,and the deformed microstructures were mainly composed of deformed grains and recovery structure.The main softening mechanism was dynamic recovery at the temperature of 573-713 K and the strain rate of 0.1-10.0s-1,but dynamic recrystallization was enhanced with the increase in temperature.展开更多
The effects of the solution treatment on the microstructure,recrystallization,texture composition and properties of 7A65-T7451(120 mm)hot rolled plates at H/2(1/2 thickness)and H/4(1/4 thickness)were studied.The resul...The effects of the solution treatment on the microstructure,recrystallization,texture composition and properties of 7A65-T7451(120 mm)hot rolled plates at H/2(1/2 thickness)and H/4(1/4 thickness)were studied.The results show that the hot rolled microstructure mainly contains a large amount of MgZn_(2) phases and minor Al_(7)Cu_(2)Fe phase.After solid solution treatments,a large amount of MgZn_(2) phases are dissolved back into the aluminum matrix.The main texture types at H/4 are R-Cube,Cube and part of Brass texture,and the main texture types at H/2 are Cube,R,and Copper texture.The qualitative analysis by Schmidt's law reveals that Copper texture at H/2 will deepen the anisotropy of plate metal properties.For the plate with the same thickness,the two-stage solution state has better mechanical properties due to the lower degree of recrystallization and stronger grain boundary strengthening effects.Under the two-stage solution system of 460℃/165 min+477℃/165 min,the composite mechanical properties of the alloy plate at H/4 are the best and the anisotropy is not obvious.The tensile strength,yield strength,and elongation along the rolling direction are 561.9 MPa,523.4 MPa,and 10.6%,respectively..展开更多
基金financially supported from the Southwest Aluminum(group)Co,.Ltd under the Project(No.JZKG20190099)。
文摘Hot deformation behavior and microstructural evolution of as-homogenized 7A65 Al alloy under isothermal compression at temperatures of 573-713 K and strain rates of 0.1-10.0 s-1were investigated.It was found that the flow stress of 7A65 Al alloy exhibited a typical dynamic recovery characteristic at high-temperature deformation conditions,and a sixth-order polynomial strain compensated Arrhenius constitutive equation was proposed to describe the flow behavior.Based on the dynamic material model and the Prasad standard,the hot processing map was established.The optimal processing conditions were within the temperature range of 633-713 K and the strain rate range of 0.1-0.5 s^(-1)when the true strain exceeded 0.6.Deformation temperature and strain rate had an obvious effect on the micros tructure evolution of 7A65Al alloy,and the deformed microstructures were mainly composed of deformed grains and recovery structure.The main softening mechanism was dynamic recovery at the temperature of 573-713 K and the strain rate of 0.1-10.0s-1,but dynamic recrystallization was enhanced with the increase in temperature.
文摘The effects of the solution treatment on the microstructure,recrystallization,texture composition and properties of 7A65-T7451(120 mm)hot rolled plates at H/2(1/2 thickness)and H/4(1/4 thickness)were studied.The results show that the hot rolled microstructure mainly contains a large amount of MgZn_(2) phases and minor Al_(7)Cu_(2)Fe phase.After solid solution treatments,a large amount of MgZn_(2) phases are dissolved back into the aluminum matrix.The main texture types at H/4 are R-Cube,Cube and part of Brass texture,and the main texture types at H/2 are Cube,R,and Copper texture.The qualitative analysis by Schmidt's law reveals that Copper texture at H/2 will deepen the anisotropy of plate metal properties.For the plate with the same thickness,the two-stage solution state has better mechanical properties due to the lower degree of recrystallization and stronger grain boundary strengthening effects.Under the two-stage solution system of 460℃/165 min+477℃/165 min,the composite mechanical properties of the alloy plate at H/4 are the best and the anisotropy is not obvious.The tensile strength,yield strength,and elongation along the rolling direction are 561.9 MPa,523.4 MPa,and 10.6%,respectively..
