Pre-stretching and annealing treatments were conducted on twin roll cast Mg-2Al-1Zn-1Ca(AZX211,in wt.%)plates with a rare earth-like texture.Varying amounts of deformation were applied along the rolling direction(RD)a...Pre-stretching and annealing treatments were conducted on twin roll cast Mg-2Al-1Zn-1Ca(AZX211,in wt.%)plates with a rare earth-like texture.Varying amounts of deformation were applied along the rolling direction(RD)and transverse direction(TD)of AZX211 alloy in order to modify its mechanical proper-ties at room temperature.The results demonstrate that pre-stretching treatment effectively enhances the yield strength(YS),especially along the RD.The strengthening mechanism is attributed to the production of a large number of dislocations and sub-grain boundaries,but the work-hardening ability of the plate will be greatly weakened.Additionally,annealing treatment substantially improves the plasticity and in-plane anisotropy and restores the work-hardening ability.The notable distinction in the pre-stretching process between different directions lies in the underlying deformation mechanism.In case of RD,de-formation is predominantly governed by the slip mechanism of{0002}{11−20}basal slip and{10−10}{11−20}prismatic slip,while along the TD,deformation is primarily controlled by{0002}{11−20}basal slip without significant twinning deformation.When a 6%pre-stretching is conducted,the initial rare earth-like texture of the sample transforms into a symmetrically distributed double-peak basal texture,accompanied by grain refinement.This texture transformation is chiefly due to the dominance of{0002}{11−20}basal slip-driven deformation.Moreover,the annealed sample maintains a strong basal texture,owing to strain-induced recrystallization.展开更多
This study investigates the influence of varying rolling reduction on the evolution of microstructure and mechanical properties of Mg–10Gd(in wt%)alloys by caliber rolling(CR).By increasing the rolling reduction from...This study investigates the influence of varying rolling reduction on the evolution of microstructure and mechanical properties of Mg–10Gd(in wt%)alloys by caliber rolling(CR).By increasing the rolling reduction from 45%to 65%,a uniform bimodal structure is obtained in which coarse grains(CGs)larger than 10μm are surrounded by fine grains(FGs).The Mg–Gd alloy subjected to 65%reduction exhibits superior mechanical properties,i.e.yield strength(YS)of~424 MPa,ultimate tensile strength(UTS)of~500 MPa and elongation(El.)of~3.3%.The synergistic improvement in strength and ductility is primarily attributed to the combined effects of low-angle grain boundary(LAGB)strengthening,precipitation strengthening,and the coordinated deformation exhibited by the bimodal structure.In addition,caliber rolling also provides a novel approach for the design of Mg alloys with uniform bimodal structures that exhibit both high strength and ductility.展开更多
基金supported by the National Natural Science Foundation of China(No.52001106)Hebei province(No.E2022202158).
文摘Pre-stretching and annealing treatments were conducted on twin roll cast Mg-2Al-1Zn-1Ca(AZX211,in wt.%)plates with a rare earth-like texture.Varying amounts of deformation were applied along the rolling direction(RD)and transverse direction(TD)of AZX211 alloy in order to modify its mechanical proper-ties at room temperature.The results demonstrate that pre-stretching treatment effectively enhances the yield strength(YS),especially along the RD.The strengthening mechanism is attributed to the production of a large number of dislocations and sub-grain boundaries,but the work-hardening ability of the plate will be greatly weakened.Additionally,annealing treatment substantially improves the plasticity and in-plane anisotropy and restores the work-hardening ability.The notable distinction in the pre-stretching process between different directions lies in the underlying deformation mechanism.In case of RD,de-formation is predominantly governed by the slip mechanism of{0002}{11−20}basal slip and{10−10}{11−20}prismatic slip,while along the TD,deformation is primarily controlled by{0002}{11−20}basal slip without significant twinning deformation.When a 6%pre-stretching is conducted,the initial rare earth-like texture of the sample transforms into a symmetrically distributed double-peak basal texture,accompanied by grain refinement.This texture transformation is chiefly due to the dominance of{0002}{11−20}basal slip-driven deformation.Moreover,the annealed sample maintains a strong basal texture,owing to strain-induced recrystallization.
基金financial support from the National Natural Science Foundation of China(51701060,52001106)Hebei Province(E2022202158),the foundation of the Strengthening Program(2019-JCJQ-142-00)。
文摘This study investigates the influence of varying rolling reduction on the evolution of microstructure and mechanical properties of Mg–10Gd(in wt%)alloys by caliber rolling(CR).By increasing the rolling reduction from 45%to 65%,a uniform bimodal structure is obtained in which coarse grains(CGs)larger than 10μm are surrounded by fine grains(FGs).The Mg–Gd alloy subjected to 65%reduction exhibits superior mechanical properties,i.e.yield strength(YS)of~424 MPa,ultimate tensile strength(UTS)of~500 MPa and elongation(El.)of~3.3%.The synergistic improvement in strength and ductility is primarily attributed to the combined effects of low-angle grain boundary(LAGB)strengthening,precipitation strengthening,and the coordinated deformation exhibited by the bimodal structure.In addition,caliber rolling also provides a novel approach for the design of Mg alloys with uniform bimodal structures that exhibit both high strength and ductility.
