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
The microstructure and mechanical properties of 2524 Al alloy after quenching in liquid nitrogen(LN_(2))were investigated by TEM and compared with those of cold water quenching.The results show that the LN_(2) quenchi...The microstructure and mechanical properties of 2524 Al alloy after quenching in liquid nitrogen(LN_(2))were investigated by TEM and compared with those of cold water quenching.The results show that the LN_(2) quenching process effectively induces the formation of dislocation loops.These loops become large and unevenly distribute after aging for 15 min.Furthermore,such loops become rapidly immobilized by the precipitation of coarse S phases after 1 h aging.The alloy quenched in LN_(2) demonstrates superior peak hardness and displays a more rapid response to subsequent aging treatments compared with the cold water-quenched one.Despite the short aging time,LN_(2)-quenched sample achieves tensile strength of 488 MPa.This enhanced strength is attributed to the strengthening effect of numerous finely dispersed Guinier-Preston-Bagaryatsky(GPB)zones,in conjunction with the inhomogeneous formation of S phase on the dislocation loops.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supported by the National Natural Science Foundation of China(No.52001106)the Natural Science Foundation of Hebei Province,China(No.E2022202158).
文摘The microstructure and mechanical properties of 2524 Al alloy after quenching in liquid nitrogen(LN_(2))were investigated by TEM and compared with those of cold water quenching.The results show that the LN_(2) quenching process effectively induces the formation of dislocation loops.These loops become large and unevenly distribute after aging for 15 min.Furthermore,such loops become rapidly immobilized by the precipitation of coarse S phases after 1 h aging.The alloy quenched in LN_(2) demonstrates superior peak hardness and displays a more rapid response to subsequent aging treatments compared with the cold water-quenched one.Despite the short aging time,LN_(2)-quenched sample achieves tensile strength of 488 MPa.This enhanced strength is attributed to the strengthening effect of numerous finely dispersed Guinier-Preston-Bagaryatsky(GPB)zones,in conjunction with the inhomogeneous formation of S phase on the dislocation loops.
