Mechanical properties and texture evolutions of the as-rolled AZ31 Mg sheets were investigated.The results show that the grains of the sheets are significantly refined after hot rolling.The mechanical properties of th...Mechanical properties and texture evolutions of the as-rolled AZ31 Mg sheets were investigated.The results show that the grains of the sheets are significantly refined after hot rolling.The mechanical properties of the as-rolled samples are enhanced due to the grain size refinement.The intensity of basal texture decreases with the increase of deformation ratio,and double-peak type basal texture is discovered in the intermediate and large strain hot rolling processes.The formation of the texture is ascribed to the activities of prismatic and non-basalslips,which is the same as the 30%rolled and 50%rolled samples.The incline of basal planes exerts an effect on the mechanical anisotropy during tension along rolling direction(RD)and transverse direction(TD)at room temperature.展开更多
Hot rolling of AZ31 Mg alloy was performed by using as-cast alloy ingot as the starting material.The microstructures and mechanical properties of the as-rolled alloy subjected to various rolling passes were investigat...Hot rolling of AZ31 Mg alloy was performed by using as-cast alloy ingot as the starting material.The microstructures and mechanical properties of the as-rolled alloy subjected to various rolling passes were investigated.The results show that the grain size of the alloy can be refined steadily with increasing rolling passes by dynamic recrystallization.With the steady refining of the grain size,both the mechanical strength and the plasticity of the alloy are improved correspondingly.In particular,when the grain size is reduced to about 5μm after 5 rolling passes,the yield strength,ultimate tensile strength and tensile fracture strain of the alloy are 211 MPa,280 MPa and 0.28 in the transverse direction,they are 200 MPa,268 MPa and 0.32 in the rolling direction,respectively.展开更多
The hydriding of as-cast Mg-5.5%Zn-0.6%Zr(ZK60 Mg)(mass fraction)alloy was achieved by room-temperature reaction milling in hydrogen,with the mechanical energy serving as the driving force for the process.The hydridin...The hydriding of as-cast Mg-5.5%Zn-0.6%Zr(ZK60 Mg)(mass fraction)alloy was achieved by room-temperature reaction milling in hydrogen,with the mechanical energy serving as the driving force for the process.The hydriding progress during milling was examined by hydrogen absorption measurement,and the microstructure change was characterized by X-ray diffraction analysis(XRD),scanning electron microscopy(SEM),and transmission electron microscopy(TEM),respectively.The results show that,by room-temperature reaction milling in hydrogen,the as-cast ZK60 Mg alloy can be fully hydrided to form a nanocrystalline MgH_(2) single-phase microstructure.In particular,the average grain size of the MgH_(2) phase obtained by room-temperature reaction milling in hydrogen for 16.2 h is about 8-10 nm,and the average particle size of the as-milled hydrided powders is 2-3μm.展开更多
The extrusion ratio is one of the key parameters for manufacturing the lead-glass fiber(Pb-GF)composite wire by coating extrusion.The effect of extrusion ratio on coating extrusion of Pb-GF composite wire was studied ...The extrusion ratio is one of the key parameters for manufacturing the lead-glass fiber(Pb-GF)composite wire by coating extrusion.The effect of extrusion ratio on coating extrusion of Pb-GF composite wire was studied by finite element numerical simulation with the use of the DEFOEM simulation software.The simulation result shows that the higher the extrusion ratio,the higher the effective stress that the glass fiber bears during extrusion.It is also observed that the extrusion force increases with the increase of the extrusion ratio.The extrusion experiment of Pb-GF composite wire reveals that extrusion ratio is changed by changing the quantity of glass fiber and composite diameter.The rule that increasing the extrusion ratio enhances the coating speed limit suggests that the load on the glass fiber increases with increasing extrusion ratio.Both the simulation and the extrusion experiments show that the extrusion force increases with increasing extrusion ratio.展开更多
The effect of Al and Zn additives on the grain size of Mg-3Ni-2MnO_(2) alloy was investigated.The nanostructured Mg-3Ni-2MnO_(2) and Mg-3Ni-2MnO_(2)-3Al-Zn were made by ball milling process under hydrogen atmosphere.T...The effect of Al and Zn additives on the grain size of Mg-3Ni-2MnO_(2) alloy was investigated.The nanostructured Mg-3Ni-2MnO_(2) and Mg-3Ni-2MnO_(2)-3Al-Zn were made by ball milling process under hydrogen atmosphere.The XRD results and TEM analysis reveal that Al and Zn additives almost have no effect on the grain size of Mg-3Ni-2MnO_(2) alloy.The present study provides us a feasibility of producing nano-structured magnesium alloys,based on hydrogenation,disproportionation,desorption and recombination(HDDR),by adding beneficial elements to hydrogen storage materials.展开更多
Nanostructured Mg-3Ni-2MnO_(2) was synthesized by ball milling elemental powders of Mg,Ni and MnO_(2) in hydrogen atmosphere.The microstructures of the powder prepared at different milling time were analyzed by X-ray ...Nanostructured Mg-3Ni-2MnO_(2) was synthesized by ball milling elemental powders of Mg,Ni and MnO_(2) in hydrogen atmosphere.The microstructures of the powder prepared at different milling time were analyzed by X-ray diffractometry(XRD), scanning electron microscopy(SEM)and high resolution electron microscopy(HREM).The milling time is the most key parameter impacting on the grain size and the microstructure of material.With prolonging the milling time,particle size becomes smaller and smaller.But after the ball milling time reaches about 20 h,reduction of grain size becomes slowly.When the milling time is more than 50 h,nanocrystalline fully forms.When the milling time is more than 80 h,there are more amorphous phases in materials.The average particle diameter of material is about 1μm and the grain size is 10-30 nm.展开更多
文摘Mechanical properties and texture evolutions of the as-rolled AZ31 Mg sheets were investigated.The results show that the grains of the sheets are significantly refined after hot rolling.The mechanical properties of the as-rolled samples are enhanced due to the grain size refinement.The intensity of basal texture decreases with the increase of deformation ratio,and double-peak type basal texture is discovered in the intermediate and large strain hot rolling processes.The formation of the texture is ascribed to the activities of prismatic and non-basalslips,which is the same as the 30%rolled and 50%rolled samples.The incline of basal planes exerts an effect on the mechanical anisotropy during tension along rolling direction(RD)and transverse direction(TD)at room temperature.
文摘Hot rolling of AZ31 Mg alloy was performed by using as-cast alloy ingot as the starting material.The microstructures and mechanical properties of the as-rolled alloy subjected to various rolling passes were investigated.The results show that the grain size of the alloy can be refined steadily with increasing rolling passes by dynamic recrystallization.With the steady refining of the grain size,both the mechanical strength and the plasticity of the alloy are improved correspondingly.In particular,when the grain size is reduced to about 5μm after 5 rolling passes,the yield strength,ultimate tensile strength and tensile fracture strain of the alloy are 211 MPa,280 MPa and 0.28 in the transverse direction,they are 200 MPa,268 MPa and 0.32 in the rolling direction,respectively.
基金Project(50574034)supported by the National Natural Science Foundation of ChinaProject(20060213016)supported by Doctoral Education Fund of Ministry of Education of China。
文摘The hydriding of as-cast Mg-5.5%Zn-0.6%Zr(ZK60 Mg)(mass fraction)alloy was achieved by room-temperature reaction milling in hydrogen,with the mechanical energy serving as the driving force for the process.The hydriding progress during milling was examined by hydrogen absorption measurement,and the microstructure change was characterized by X-ray diffraction analysis(XRD),scanning electron microscopy(SEM),and transmission electron microscopy(TEM),respectively.The results show that,by room-temperature reaction milling in hydrogen,the as-cast ZK60 Mg alloy can be fully hydrided to form a nanocrystalline MgH_(2) single-phase microstructure.In particular,the average grain size of the MgH_(2) phase obtained by room-temperature reaction milling in hydrogen for 16.2 h is about 8-10 nm,and the average particle size of the as-milled hydrided powders is 2-3μm.
文摘The extrusion ratio is one of the key parameters for manufacturing the lead-glass fiber(Pb-GF)composite wire by coating extrusion.The effect of extrusion ratio on coating extrusion of Pb-GF composite wire was studied by finite element numerical simulation with the use of the DEFOEM simulation software.The simulation result shows that the higher the extrusion ratio,the higher the effective stress that the glass fiber bears during extrusion.It is also observed that the extrusion force increases with the increase of the extrusion ratio.The extrusion experiment of Pb-GF composite wire reveals that extrusion ratio is changed by changing the quantity of glass fiber and composite diameter.The rule that increasing the extrusion ratio enhances the coating speed limit suggests that the load on the glass fiber increases with increasing extrusion ratio.Both the simulation and the extrusion experiments show that the extrusion force increases with increasing extrusion ratio.
基金Project(DCQQ24404018)supported by Scientific and Technological Program of Heilongjiang Province,China。
文摘The effect of Al and Zn additives on the grain size of Mg-3Ni-2MnO_(2) alloy was investigated.The nanostructured Mg-3Ni-2MnO_(2) and Mg-3Ni-2MnO_(2)-3Al-Zn were made by ball milling process under hydrogen atmosphere.The XRD results and TEM analysis reveal that Al and Zn additives almost have no effect on the grain size of Mg-3Ni-2MnO_(2) alloy.The present study provides us a feasibility of producing nano-structured magnesium alloys,based on hydrogenation,disproportionation,desorption and recombination(HDDR),by adding beneficial elements to hydrogen storage materials.
文摘Nanostructured Mg-3Ni-2MnO_(2) was synthesized by ball milling elemental powders of Mg,Ni and MnO_(2) in hydrogen atmosphere.The microstructures of the powder prepared at different milling time were analyzed by X-ray diffractometry(XRD), scanning electron microscopy(SEM)and high resolution electron microscopy(HREM).The milling time is the most key parameter impacting on the grain size and the microstructure of material.With prolonging the milling time,particle size becomes smaller and smaller.But after the ball milling time reaches about 20 h,reduction of grain size becomes slowly.When the milling time is more than 50 h,nanocrystalline fully forms.When the milling time is more than 80 h,there are more amorphous phases in materials.The average particle diameter of material is about 1μm and the grain size is 10-30 nm.
