3%Y_(2)O_(3)p/ZGK200 composites were subjected to unidirectional rolling(UR)and cross rolling(CR)at 400℃and 350℃followed by annealing at 300℃for 1 h.The microstructure,texture and mechanical properties of rolled an...3%Y_(2)O_(3)p/ZGK200 composites were subjected to unidirectional rolling(UR)and cross rolling(CR)at 400℃and 350℃followed by annealing at 300℃for 1 h.The microstructure,texture and mechanical properties of rolled and annealed composites were systematically studied.The rolled composites exhibited a heterogeneous microstructure,consisting of deformed grains elongated along rolling direction(RD)and Y_(2)O_(3)particles bands distributed along RD.After annealing,static recrystallization(SRX)occurred and most deformed grains transformed into equiaxed grains.A non-basal texture with two strong T-texture components was obtained after UR while a non-basal elliptical/circle texture with circle multi-peaks was obtained after CR,indicating that rolling path had great influences on texture of the composites.After annealing process,R-texture component disappeared or weakened,as results,a non-basal texture with double peaks tilting from normal direction(ND)to transverse direction(TD)and a more random non-basal texture with circle multi-peaks were obtained for UR and CR composites,respectively.The yield strength of rolled composites after UR showed obvious anisotropy along RD and TD while a low anisotropic yield strength was obtained after CR.Some Y_(2)O_(3)particles broke during rolling.The fracture of the composites was attributed to the existence of Y_(2)O_(3)clusters and interfacial debonding between particles and matrix during tension,as a result,the ductility was not as superior as matrix alloy.展开更多
Mechanical properties and microstructures of unidirectionally and tandem rolled alumina dispersion strengthened copper(ADSC)alloys under different conditions were investigated by tensile test,optical microscopy(OM),tr...Mechanical properties and microstructures of unidirectionally and tandem rolled alumina dispersion strengthened copper(ADSC)alloys under different conditions were investigated by tensile test,optical microscopy(OM),transmission electron microscopy(TEM)and scanning electron microscopy(SEM).For unidirectionally rolled ADSC alloys,their strengths and elongations in the longitudinal direction are higher than those in the transverse direction under both cold rolling and annealing conditions.Once fracture appears in their longitudinal stress—strain curves,sudden reduction of overall stress level before complete fracture can be observed in the transverse tensile curves.The anisotropy of mechanical properties for the ADSC alloy can be greatly improved by tandem cold rolling.And no sudden reduction of overall stress level appears in the stress—strain curves for tandem rolled ADSC alloys.The differences of their microstructures and tensile fractures were analyzed.In order to compare the differences of tensile fracture mechanism in different directions,longitudinal and transverse fracture models for unidirectionally rolled ADSC alloys were also introduced.展开更多
基金financial supports from the Natural Science Foundation of Shandong Province(ZR2021ME241)the Natural Science Foundation of Liaoning Province(No.2020-MS-004)+2 种基金the National Natural Science Foundation of China(NSFC,Nos.51601193 and 51701218)State Key Program of National Natural Science of China(No.51531002)National Key Research and Development Program of China(No.2016YFB0301104).
文摘3%Y_(2)O_(3)p/ZGK200 composites were subjected to unidirectional rolling(UR)and cross rolling(CR)at 400℃and 350℃followed by annealing at 300℃for 1 h.The microstructure,texture and mechanical properties of rolled and annealed composites were systematically studied.The rolled composites exhibited a heterogeneous microstructure,consisting of deformed grains elongated along rolling direction(RD)and Y_(2)O_(3)particles bands distributed along RD.After annealing,static recrystallization(SRX)occurred and most deformed grains transformed into equiaxed grains.A non-basal texture with two strong T-texture components was obtained after UR while a non-basal elliptical/circle texture with circle multi-peaks was obtained after CR,indicating that rolling path had great influences on texture of the composites.After annealing process,R-texture component disappeared or weakened,as results,a non-basal texture with double peaks tilting from normal direction(ND)to transverse direction(TD)and a more random non-basal texture with circle multi-peaks were obtained for UR and CR composites,respectively.The yield strength of rolled composites after UR showed obvious anisotropy along RD and TD while a low anisotropic yield strength was obtained after CR.Some Y_(2)O_(3)particles broke during rolling.The fracture of the composites was attributed to the existence of Y_(2)O_(3)clusters and interfacial debonding between particles and matrix during tension,as a result,the ductility was not as superior as matrix alloy.
基金Projects(2002AA302505,2006AA03Z517)supported by the National High-Tech Research and Development Program of China
文摘Mechanical properties and microstructures of unidirectionally and tandem rolled alumina dispersion strengthened copper(ADSC)alloys under different conditions were investigated by tensile test,optical microscopy(OM),transmission electron microscopy(TEM)and scanning electron microscopy(SEM).For unidirectionally rolled ADSC alloys,their strengths and elongations in the longitudinal direction are higher than those in the transverse direction under both cold rolling and annealing conditions.Once fracture appears in their longitudinal stress—strain curves,sudden reduction of overall stress level before complete fracture can be observed in the transverse tensile curves.The anisotropy of mechanical properties for the ADSC alloy can be greatly improved by tandem cold rolling.And no sudden reduction of overall stress level appears in the stress—strain curves for tandem rolled ADSC alloys.The differences of their microstructures and tensile fractures were analyzed.In order to compare the differences of tensile fracture mechanism in different directions,longitudinal and transverse fracture models for unidirectionally rolled ADSC alloys were also introduced.
