The influence of cryogenic treatment on the mechanical properties of the extruded Mg-Gd-Y-Zr(Mn) alloys was investigated by the tensile tests, scanning electron microscopy(SEM), transmission electron microscopy(TEM), ...The influence of cryogenic treatment on the mechanical properties of the extruded Mg-Gd-Y-Zr(Mn) alloys was investigated by the tensile tests, scanning electron microscopy(SEM), transmission electron microscopy(TEM), and energy dispersive X-ray spectroscopy (EDS). The results show that the mechanical properties of both alloys are improved greatly during the in situ tensile test by soaking the samples in liquid nitrogen for 10 min. The ultimate tensile strength, yield tensile strength and elongation of cryogenic treated magnesium alloy added with zirconium or manganese are largely elevated. And remarkable microstructure change is observed in both alloys by cryogenic treatment. There are a large number of twins,rod-like, tree-like and chrysanthemum-like precipitated phases in the microstructures and the fracture surfaces exhibit the characteristics of ductile rupture when they are observed at room temperature.展开更多
The ignition-proof mechanism of ZM5 magnesium alloy added with 0.1% (mass fraction) rare earth (RE) was investigated. The oxide scales and substrates were characterized by scanning electronic microscope (SEM), X...The ignition-proof mechanism of ZM5 magnesium alloy added with 0.1% (mass fraction) rare earth (RE) was investigated. The oxide scales and substrates were characterized by scanning electronic microscope (SEM), X-ray diffraction (XRD), energy dispersive spectrometer (EDS) and tensile test. And an oxidation model of ZM5 alloy with RE was established. The results show that the ignition temperature of ZM5 alloy is particularly elevated from 654 to 823 ℃, the microstructure is refined, and the tensile strength is slightly improved from 168.2 to 174.6 MPa by adding 0.1% RE. A double-layer oxidation film formed on the alloy surface under high temperature mainly consists of MgO, RE203 and A1203, which is 2.5-3.5 μm in thickness. It is found that the forming of protective oxidation film on the thermodynamics is attributed to RE elements congregating on the surface of molten Mg alloy.展开更多
基金Project (51412020304QT7106) supported by the National Defense Pre-investigation Foundation of ChinaProject(2003AA741043) supported by the National High-Tech Research and Development Program of ChinaProject(5133001E) supported by the State Key Fundamental Research and Development Program of China
文摘The influence of cryogenic treatment on the mechanical properties of the extruded Mg-Gd-Y-Zr(Mn) alloys was investigated by the tensile tests, scanning electron microscopy(SEM), transmission electron microscopy(TEM), and energy dispersive X-ray spectroscopy (EDS). The results show that the mechanical properties of both alloys are improved greatly during the in situ tensile test by soaking the samples in liquid nitrogen for 10 min. The ultimate tensile strength, yield tensile strength and elongation of cryogenic treated magnesium alloy added with zirconium or manganese are largely elevated. And remarkable microstructure change is observed in both alloys by cryogenic treatment. There are a large number of twins,rod-like, tree-like and chrysanthemum-like precipitated phases in the microstructures and the fracture surfaces exhibit the characteristics of ductile rupture when they are observed at room temperature.
基金Project(2004BB8429) supported by Chongqing Municipal Science and Technology Commission, China
文摘The ignition-proof mechanism of ZM5 magnesium alloy added with 0.1% (mass fraction) rare earth (RE) was investigated. The oxide scales and substrates were characterized by scanning electronic microscope (SEM), X-ray diffraction (XRD), energy dispersive spectrometer (EDS) and tensile test. And an oxidation model of ZM5 alloy with RE was established. The results show that the ignition temperature of ZM5 alloy is particularly elevated from 654 to 823 ℃, the microstructure is refined, and the tensile strength is slightly improved from 168.2 to 174.6 MPa by adding 0.1% RE. A double-layer oxidation film formed on the alloy surface under high temperature mainly consists of MgO, RE203 and A1203, which is 2.5-3.5 μm in thickness. It is found that the forming of protective oxidation film on the thermodynamics is attributed to RE elements congregating on the surface of molten Mg alloy.