0.5% （molar fraction） Sb was added to Mg61Cu28Gd11 glass forming alloy to improve its thermal stability and corrosion resistance. The crystallization kinetics of Mg61Cu28Gd11 and （Mg0.61Cu0.28Gd0.11）99.5Sb0.5 amor...0.5% （molar fraction） Sb was added to Mg61Cu28Gd11 glass forming alloy to improve its thermal stability and corrosion resistance. The crystallization kinetics of Mg61Cu28Gd11 and （Mg0.61Cu0.28Gd0.11）99.5Sb0.5 amorphous alloys was investigated under continuous heating. The temperatures of glass transition, onset and peak crystallization for the two glasses exhibit strong heating-rate dependence. The activation energies for the onset and peak crystallization were determined based on the Oawza plots. Vogel-Fulcher-Tamman equation analysis shows that the larger strength parameter and much longer relaxation time are obtained due to the Sb addition. The corrosion properties of the two glassy alloys were studied by means of potentiodynamic and immersion tests. Compared with the parent alloy, （Mg0.61Cu0.28Gd0.11）99.5Sb0.5 glassy alloy exhibits a superior corrosion resistance in Cl--containing alkaline solution, as indicated by the lower passive current density and corrosion rate. Based on the point defect model, the effect mechanism of Sb addition on corrosion resistance of Mg-Cu-Gd glassy alloy is carefully identified.展开更多
The effects of Sn content on microstructure and tensile properties of as-cast and as-extruded Mg-8Li-3Al-(1,2,3)Sn(wt.%)alloys were investigated by X-ray diffractometry(XRD),optical microscopy(OM),scanning electron mi...The effects of Sn content on microstructure and tensile properties of as-cast and as-extruded Mg-8Li-3Al-(1,2,3)Sn(wt.%)alloys were investigated by X-ray diffractometry(XRD),optical microscopy(OM),scanning electron microscopy(SEM)and tensile test.It is found that,as-cast Mg-8Li-3Al-(1,2,3)Sn alloys consist ofα-Mg+β-Li duplex matrix,MgLiAl2 and Li2Mg Sn phases.Increasing Sn content leads to grain refinement ofα-Mg dendrites and increase in content of Li2MgSn phase.During hot extrusion,complete dynamic recrystallization(DRX)takes place inβ-Li phase while incomplete DRX takes place inα-Mg phase.As Sn content is increased,the volume fraction of DRXedα-Mg grains is increased and the average grain size of DRXedα-Mg grains is decreased.Increasing Sn content is beneficial to strength but harmful to ductility for as-cast Mg-8Li-3Al-(1,2,3)Sn alloys.Tensile properties of Mg-8Li-3Al-(1,2,3)Sn alloys are improved significantly via hot extrusion and Mg-8Li-3Al-2Sn alloy exhibits the best tensile properties.展开更多
基金Project (1006-56Y1064) supported by the Nanjing University of Aeronautics and Astronautics Research Funding, China
文摘0.5% （molar fraction） Sb was added to Mg61Cu28Gd11 glass forming alloy to improve its thermal stability and corrosion resistance. The crystallization kinetics of Mg61Cu28Gd11 and （Mg0.61Cu0.28Gd0.11）99.5Sb0.5 amorphous alloys was investigated under continuous heating. The temperatures of glass transition, onset and peak crystallization for the two glasses exhibit strong heating-rate dependence. The activation energies for the onset and peak crystallization were determined based on the Oawza plots. Vogel-Fulcher-Tamman equation analysis shows that the larger strength parameter and much longer relaxation time are obtained due to the Sb addition. The corrosion properties of the two glassy alloys were studied by means of potentiodynamic and immersion tests. Compared with the parent alloy, （Mg0.61Cu0.28Gd0.11）99.5Sb0.5 glassy alloy exhibits a superior corrosion resistance in Cl--containing alkaline solution, as indicated by the lower passive current density and corrosion rate. Based on the point defect model, the effect mechanism of Sb addition on corrosion resistance of Mg-Cu-Gd glassy alloy is carefully identified.
基金Project(51601076)supported by the National Natural Science Foundation of ChinaProject(17KJA430005)supported by the Natural Science Fund for Colleges and Universities in Jiangsu Province,ChinaProject(2019M650096)supported by China Postdoctoral Science Foundation。
文摘The effects of Sn content on microstructure and tensile properties of as-cast and as-extruded Mg-8Li-3Al-(1,2,3)Sn(wt.%)alloys were investigated by X-ray diffractometry(XRD),optical microscopy(OM),scanning electron microscopy(SEM)and tensile test.It is found that,as-cast Mg-8Li-3Al-(1,2,3)Sn alloys consist ofα-Mg+β-Li duplex matrix,MgLiAl2 and Li2Mg Sn phases.Increasing Sn content leads to grain refinement ofα-Mg dendrites and increase in content of Li2MgSn phase.During hot extrusion,complete dynamic recrystallization(DRX)takes place inβ-Li phase while incomplete DRX takes place inα-Mg phase.As Sn content is increased,the volume fraction of DRXedα-Mg grains is increased and the average grain size of DRXedα-Mg grains is decreased.Increasing Sn content is beneficial to strength but harmful to ductility for as-cast Mg-8Li-3Al-(1,2,3)Sn alloys.Tensile properties of Mg-8Li-3Al-(1,2,3)Sn alloys are improved significantly via hot extrusion and Mg-8Li-3Al-2Sn alloy exhibits the best tensile properties.
基金The Funding of Jiangsu Innovation Program for Graduate Education(CXZZ13_0160)the Fundamental Research Funds for the Central Universities,Nanjing University of Aeronautics and Astronautics Research Funding(NS2013060)the Priority Academic Program Development of Jiangsu Higher Education Institutions
