Microstructure and mechanical properties of aged Mg-10Gd-2Y-0.4Zr-0.4Ag alloy sheets prepared by different rolling routes were investigated.The results showed that the cross rolling aged(CRA)sheet possesses larger gra...Microstructure and mechanical properties of aged Mg-10Gd-2Y-0.4Zr-0.4Ag alloy sheets prepared by different rolling routes were investigated.The results showed that the cross rolling aged(CRA)sheet possesses larger grain size than unidirectional rolling aged(URA)sheet due to the occurrence of dynamic recovery during rolling which reduces the dislocation density and delays dynamic recrystallization(DRX).The URA sheet has basal texture and RD favored texture while CRA sheet has multiple-peak texture.Both sheets precipitate β'phase and CRA sheet exhibits a stronger aging response.The CRA sheet has higher yield strength and tensile strength than URA sheet,with reduced yield strength anisotropy but increased tensile strength anisotropy.Taking into account different strengthening mechanisms,although the finer grain size of URA sheet enhances grain boundary strengthening,CRA sheet is more responsive to aging,leading to superior aging-precipitated phase strengthening and consequently higher yield strength.展开更多
The effects of trace Ag on the tensile strength and creep resistance of Mg-7.5Gd-1.5Y-0.4Zr(wt.%)extrusion bars were investigated at temperatures of 175-275℃,via tensile tests and creep tests,electron back-scatter di...The effects of trace Ag on the tensile strength and creep resistance of Mg-7.5Gd-1.5Y-0.4Zr(wt.%)extrusion bars were investigated at temperatures of 175-275℃,via tensile tests and creep tests,electron back-scatter diffraction,and transmission electron microscopy.Adding trace Ag improves the tensile strength and creep resistance of Mg-Gd-Y-Zr alloys at elevated temperatures.During the creep process,precipitate-free zones(PFZs)are formed near grain boundaries and perpendicular to the loading direction,while chain-likeβ′-Mg7RE precipitates are distributed in a special direction([1010])in grain interior.After adding Ag element,the creep resistance of the Mg-Gd-Y-Zr-Ag is improved due to the suppression of dislocation movement by the synergistic effect of narrower PFZs,finerβ′-Mg7RE precipitates in the grain interior and more stable β-Mg_(5)RE phase located on the grain boundaries.展开更多
Mg-Gd alloy particle has exhibited its unique combustion properties as the fuel of Mg/Teflon/Viton(MTV).Mg-Gd alloy/Teflon/Viton(MGTV)could burn at lower ambient pressure than MTV.To further investigate the reaction o...Mg-Gd alloy particle has exhibited its unique combustion properties as the fuel of Mg/Teflon/Viton(MTV).Mg-Gd alloy/Teflon/Viton(MGTV)could burn at lower ambient pressure than MTV.To further investigate the reaction of MGTV in air,it was investigated via thermo gravity-differential scanning calorimetry(TG-DSC).Meanwhile,the morphologies and element distributions on the alloy surface during the reaction of MGTV in air were investigated via scanning electronic microscope-mapping-electronic differential spectrometer.Meanwhile,a similar experimental protocol on the Mg-Gd alloy particle during oxidation was also applied.The results showed that owning to a protective oxide shell,the onset oxidation temperature of Mg-Gd alloy is higher than Mg.However,the onset oxidation temperature of the exceeded Mg-Gd alloy in MGTV is significantly lower than that of the exceeded Mg in MTV.It was due to the existence of GdOF,which could significantly lower the oxidation temperature of the exceeded fuel.Furthermore,a possible reaction mechanism was proposed.The fascinating oxidation properties of Mg-Gd alloy suggested its promising applications in energetic materials.展开更多
基金Project(2023GK2020)supported by the Key Research and Development Program of Hunan Province,China。
文摘Microstructure and mechanical properties of aged Mg-10Gd-2Y-0.4Zr-0.4Ag alloy sheets prepared by different rolling routes were investigated.The results showed that the cross rolling aged(CRA)sheet possesses larger grain size than unidirectional rolling aged(URA)sheet due to the occurrence of dynamic recovery during rolling which reduces the dislocation density and delays dynamic recrystallization(DRX).The URA sheet has basal texture and RD favored texture while CRA sheet has multiple-peak texture.Both sheets precipitate β'phase and CRA sheet exhibits a stronger aging response.The CRA sheet has higher yield strength and tensile strength than URA sheet,with reduced yield strength anisotropy but increased tensile strength anisotropy.Taking into account different strengthening mechanisms,although the finer grain size of URA sheet enhances grain boundary strengthening,CRA sheet is more responsive to aging,leading to superior aging-precipitated phase strengthening and consequently higher yield strength.
基金supported by the National Key R&D Program of China(No.2021YFB3701100)。
文摘The effects of trace Ag on the tensile strength and creep resistance of Mg-7.5Gd-1.5Y-0.4Zr(wt.%)extrusion bars were investigated at temperatures of 175-275℃,via tensile tests and creep tests,electron back-scatter diffraction,and transmission electron microscopy.Adding trace Ag improves the tensile strength and creep resistance of Mg-Gd-Y-Zr alloys at elevated temperatures.During the creep process,precipitate-free zones(PFZs)are formed near grain boundaries and perpendicular to the loading direction,while chain-likeβ′-Mg7RE precipitates are distributed in a special direction([1010])in grain interior.After adding Ag element,the creep resistance of the Mg-Gd-Y-Zr-Ag is improved due to the suppression of dislocation movement by the synergistic effect of narrower PFZs,finerβ′-Mg7RE precipitates in the grain interior and more stable β-Mg_(5)RE phase located on the grain boundaries.
文摘Mg-Gd alloy particle has exhibited its unique combustion properties as the fuel of Mg/Teflon/Viton(MTV).Mg-Gd alloy/Teflon/Viton(MGTV)could burn at lower ambient pressure than MTV.To further investigate the reaction of MGTV in air,it was investigated via thermo gravity-differential scanning calorimetry(TG-DSC).Meanwhile,the morphologies and element distributions on the alloy surface during the reaction of MGTV in air were investigated via scanning electronic microscope-mapping-electronic differential spectrometer.Meanwhile,a similar experimental protocol on the Mg-Gd alloy particle during oxidation was also applied.The results showed that owning to a protective oxide shell,the onset oxidation temperature of Mg-Gd alloy is higher than Mg.However,the onset oxidation temperature of the exceeded Mg-Gd alloy in MGTV is significantly lower than that of the exceeded Mg in MTV.It was due to the existence of GdOF,which could significantly lower the oxidation temperature of the exceeded fuel.Furthermore,a possible reaction mechanism was proposed.The fascinating oxidation properties of Mg-Gd alloy suggested its promising applications in energetic materials.
