The effects of trace Ag element on the precipitation behaviors and mechanical properties of the Mg−7.5Gd−1.5Y−0.4Zr(wt.%)alloy by means of tensile test,X-ray diffractometry,scanning electron microscopy,electron backsc...The effects of trace Ag element on the precipitation behaviors and mechanical properties of the Mg−7.5Gd−1.5Y−0.4Zr(wt.%)alloy by means of tensile test,X-ray diffractometry,scanning electron microscopy,electron backscattered diffractometry,and scanning transmission electron microscopy.There is an unusual texture(á0001ñ//extrusion direction)in the extruded Mg−Gd−Y−Zr alloys containing 0.5 wt.%Ag.During the aging periods at 225℃,the addition of the trace Ag does not form new precipitates,just accelerates aging kinetics,and refinesβ′precipitates,thereby increasing the number density of theβ′precipitates by Ag-clusters.Moreover,the Mg−Gd−Y−Zr alloy containing 0.5 wt.%Ag shows the most excellent synergy of strength and plasticity(408 MPa of ultimate tensile strength,265 MPa of yield strength,and 12.9%of elongation to failure)after peak-aging.展开更多
A single crystal sample of cubic lead fluoride doped with gadolinium （β-PbF2∶Gd） was prepared by use of the Bridgman-Stockbarger method. The crystal samples for testing with dimension of *J20 mm×20 mm long we...A single crystal sample of cubic lead fluoride doped with gadolinium （β-PbF2∶Gd） was prepared by use of the Bridgman-Stockbarger method. The crystal samples for testing with dimension of *J20 mm×20 mm long were all polished. The dopant level of gadolinium is 0.15wt%. The light output and decay time of the samples were measured in the lab using 137 Cs source and 1 GeV test beam at AGS respectively. Experimental results indicated that β-PbF2∶Gd crystal produces a weak scintillation emission at room temperature corresponding to a light output of ～6 photoelectrons per MeV and most of the light is collected within a gate of 30 ns. There is no evidence of any significant slow component extending out of 1 μs. In the X-ray excited emission spectra of β-PbF2∶Gd at room temperature, two emission peaks, 277 nm and 312 nm, were found and corresponded to the transition of 6IJ→ 8 S 7/2 and 6PJ→ 8S 7/2 of Gd 3+ ions, respectively.展开更多
基金financial supports from the National Natural Science Foundation of China (Nos. 51574291, 51874367)。
文摘The effects of trace Ag element on the precipitation behaviors and mechanical properties of the Mg−7.5Gd−1.5Y−0.4Zr(wt.%)alloy by means of tensile test,X-ray diffractometry,scanning electron microscopy,electron backscattered diffractometry,and scanning transmission electron microscopy.There is an unusual texture(á0001ñ//extrusion direction)in the extruded Mg−Gd−Y−Zr alloys containing 0.5 wt.%Ag.During the aging periods at 225℃,the addition of the trace Ag does not form new precipitates,just accelerates aging kinetics,and refinesβ′precipitates,thereby increasing the number density of theβ′precipitates by Ag-clusters.Moreover,the Mg−Gd−Y−Zr alloy containing 0.5 wt.%Ag shows the most excellent synergy of strength and plasticity(408 MPa of ultimate tensile strength,265 MPa of yield strength,and 12.9%of elongation to failure)after peak-aging.
文摘A single crystal sample of cubic lead fluoride doped with gadolinium （β-PbF2∶Gd） was prepared by use of the Bridgman-Stockbarger method. The crystal samples for testing with dimension of *J20 mm×20 mm long were all polished. The dopant level of gadolinium is 0.15wt%. The light output and decay time of the samples were measured in the lab using 137 Cs source and 1 GeV test beam at AGS respectively. Experimental results indicated that β-PbF2∶Gd crystal produces a weak scintillation emission at room temperature corresponding to a light output of ～6 photoelectrons per MeV and most of the light is collected within a gate of 30 ns. There is no evidence of any significant slow component extending out of 1 μs. In the X-ray excited emission spectra of β-PbF2∶Gd at room temperature, two emission peaks, 277 nm and 312 nm, were found and corresponded to the transition of 6IJ→ 8 S 7/2 and 6PJ→ 8S 7/2 of Gd 3+ ions, respectively.
