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
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)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.
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.
