Mg-6Al-2Sr alloys with different Sm contents(0%, 0.5%, 1%, 1.5%, 2%, mass fraction) were prepared by melting and casting method. The effects of Sm on the microstructure and mechanical properties of as-cast Mg-6Al-2Sr ...Mg-6Al-2Sr alloys with different Sm contents(0%, 0.5%, 1%, 1.5%, 2%, mass fraction) were prepared by melting and casting method. The effects of Sm on the microstructure and mechanical properties of as-cast Mg-6Al-2Sr alloys were studied by optical microscope, scanning electron microscope, energy dispersive spectrometer, transmission electron microscope, X-ray diffraction and tensile test. The results show that the microstructure of as-cast Mg-6Al-2Sr alloy is composed of α-Mg, Mg_(17)Al_(12), Mg_(13)Al_(3)Sr and lamellar acicular Al_(4)Sr phase. After adding Sm element, granular block Al2Sm phase appears in the grain. With the increase of Sm content, the discontinuous long strip reticular Mg_(17)Al_(12)phase and the lamellar acicular Al4Sr phase gradually decrease, and the Al_(2)Sm phase increases and distributes more dispersedly, so the alloy microstructure is continuously refined. The average grain size of the alloys decreases at first and then increases with the increase of Sm content. When the Sm content is 1.5 wt%, the average grain size reaches the minimum value of 94.6 μm. With the increase of Sm content, the mechanical properties of the alloy at room temperature first increase and then decrease. When the Sm content is 1.5 wt%, the alloy has the best comprehensive mechanical properties at room temperature.展开更多
The microstructural evolution and mechanical properties of high speed indirect-extruded Mg-5%Sn-(1, 2, 4) Zn(mass fraction, %) alloys were investigated by optical microscopy(OM), X-ray diffraction(XRD), scanning elect...The microstructural evolution and mechanical properties of high speed indirect-extruded Mg-5%Sn-(1, 2, 4) Zn(mass fraction, %) alloys were investigated by optical microscopy(OM), X-ray diffraction(XRD), scanning electron microscopy(SEM), differential thermal analysis(DTA) and a static tension tester. All the studied alloys can be extruded successfully at a high speed of 10 m/min. The grain size, area fraction of particles and tensile properties are found to be greatly affected by the extrusion speed and Zn content, resulting in tensile properties showing lower strength and ductility as the extrusion speed increases and Zn content decreases. The dependence of grain size and tensile properties on the second phase particles is also discussed.展开更多
The casting-solid extrusion forging plus semi-solid partial remelting route is used to improve the properties of AZ31 magnesium alloy products.The effect of remelting temperature and holding time on the microstructure...The casting-solid extrusion forging plus semi-solid partial remelting route is used to improve the properties of AZ31 magnesium alloy products.The effect of remelting temperature and holding time on the microstructure of AZ31 magnesium alloy is studied.Furthermore,the properties of AZ31 magnesium alloy components produced by the casting-solid extru.sion forging plus partial remelting route are examined.The results show that the AZ31 components have very good smooth surface and are formed completely.The increases in holding time and remelting temperature result in the formation of spheroidal grains surrounded by liquid phases.The best combination of properties of thixoforged alloy is290 MPa of tensile strength,220 MPa of yield strength and 10%of percentage elongation.展开更多
Mg–8Li–3Al–0.7Si alloy was prepared by casting and deformed by hot extrusion in this study.And the microstructure of as-cast and extruded specimens was analyzed with OM,XRD,SEM and EDS.Results show that the specime...Mg–8Li–3Al–0.7Si alloy was prepared by casting and deformed by hot extrusion in this study.And the microstructure of as-cast and extruded specimens was analyzed with OM,XRD,SEM and EDS.Results show that the specimens are composed ofα-Mg,β-Li,AlLi,MgLiAl2 and Mg2Si phases.In as-extruded specimen,the microstructure is refined and theβ-Li phase has the effect of coordination during deformation.After hot extrusion,Chinese script Mg2Si phase is crushed into block-like and distributes uniformly in the matrix.Mechanical properties results show that the strength and elongation are both improved after hot extrusion.展开更多
基金Project(51975167) supported by the National Natural Science Foundation,China。
文摘Mg-6Al-2Sr alloys with different Sm contents(0%, 0.5%, 1%, 1.5%, 2%, mass fraction) were prepared by melting and casting method. The effects of Sm on the microstructure and mechanical properties of as-cast Mg-6Al-2Sr alloys were studied by optical microscope, scanning electron microscope, energy dispersive spectrometer, transmission electron microscope, X-ray diffraction and tensile test. The results show that the microstructure of as-cast Mg-6Al-2Sr alloy is composed of α-Mg, Mg_(17)Al_(12), Mg_(13)Al_(3)Sr and lamellar acicular Al_(4)Sr phase. After adding Sm element, granular block Al2Sm phase appears in the grain. With the increase of Sm content, the discontinuous long strip reticular Mg_(17)Al_(12)phase and the lamellar acicular Al4Sr phase gradually decrease, and the Al_(2)Sm phase increases and distributes more dispersedly, so the alloy microstructure is continuously refined. The average grain size of the alloys decreases at first and then increases with the increase of Sm content. When the Sm content is 1.5 wt%, the average grain size reaches the minimum value of 94.6 μm. With the increase of Sm content, the mechanical properties of the alloy at room temperature first increase and then decrease. When the Sm content is 1.5 wt%, the alloy has the best comprehensive mechanical properties at room temperature.
基金Project(2012R1A1A1012802) supported by Basic Science Research Program through the National Research Foundation(NRF)of Korea funded by the Ministry of Education,Science and TechnologyProject(2013021013-4) supported by Shanxi Province Science Foundation for Youths,China+1 种基金Project supported by Advanced Programs of Department of Human Resources and Social Security of Shanxi Province for Returned ScholarsProject(2012L003) supported by Foundation for Young Scholars of Taiyuan University of Technology,China
文摘The microstructural evolution and mechanical properties of high speed indirect-extruded Mg-5%Sn-(1, 2, 4) Zn(mass fraction, %) alloys were investigated by optical microscopy(OM), X-ray diffraction(XRD), scanning electron microscopy(SEM), differential thermal analysis(DTA) and a static tension tester. All the studied alloys can be extruded successfully at a high speed of 10 m/min. The grain size, area fraction of particles and tensile properties are found to be greatly affected by the extrusion speed and Zn content, resulting in tensile properties showing lower strength and ductility as the extrusion speed increases and Zn content decreases. The dependence of grain size and tensile properties on the second phase particles is also discussed.
文摘The casting-solid extrusion forging plus semi-solid partial remelting route is used to improve the properties of AZ31 magnesium alloy products.The effect of remelting temperature and holding time on the microstructure of AZ31 magnesium alloy is studied.Furthermore,the properties of AZ31 magnesium alloy components produced by the casting-solid extru.sion forging plus partial remelting route are examined.The results show that the AZ31 components have very good smooth surface and are formed completely.The increases in holding time and remelting temperature result in the formation of spheroidal grains surrounded by liquid phases.The best combination of properties of thixoforged alloy is290 MPa of tensile strength,220 MPa of yield strength and 10%of percentage elongation.
基金Project(51601024)supported by the National Natural Science Foundation,ChinaProjects(2016YFB0700403,2016YFB0301100)supported by the National Key Research and Development Program of China+1 种基金Project(cstc2016jcyj A0418)supported by the Chongqing Research Program of Basic Research and Frontier Technology,ChinaProject(106112016CDJXZ138811)supported by the Fundamental Research Funds for the Central Universities,China
文摘Mg–8Li–3Al–0.7Si alloy was prepared by casting and deformed by hot extrusion in this study.And the microstructure of as-cast and extruded specimens was analyzed with OM,XRD,SEM and EDS.Results show that the specimens are composed ofα-Mg,β-Li,AlLi,MgLiAl2 and Mg2Si phases.In as-extruded specimen,the microstructure is refined and theβ-Li phase has the effect of coordination during deformation.After hot extrusion,Chinese script Mg2Si phase is crushed into block-like and distributes uniformly in the matrix.Mechanical properties results show that the strength and elongation are both improved after hot extrusion.
