The microstructure of CaO-P_2O_5-SiO_2-MgO-F^- glass-ceramics duringcrystallization were investigated and the crystallized phases were identified with DTA (DifferentialThermal Analysis), SEM (Scanning Electron Microsc...The microstructure of CaO-P_2O_5-SiO_2-MgO-F^- glass-ceramics duringcrystallization were investigated and the crystallized phases were identified with DTA (DifferentialThermal Analysis), SEM (Scanning Electron Microscope) and XRD (X- ray Diffraction) techniques. Themechanical properties such as bending strength and fracture toughness, as well as their changes withadvancing crystallization were determined. The results show that the changes of the mechanicalproperties are correlated with the microstructures. The sample heated up to 810 deg C and soaked for4 h has smaller crystalline size and less volum fraction of fluorophlogopite, so it has higherbending strength (about 190 MPa), and higher crack toughness (about 2.63 MPa centre dot m^1/2).展开更多
V2O5 films were prepared on silicon wafers by DC magnetron sputtering and post-annealing under various conditions. The influence of depositing and post-annealing temperatures on microstructure of V2O5 films was studie...V2O5 films were prepared on silicon wafers by DC magnetron sputtering and post-annealing under various conditions. The influence of depositing and post-annealing temperatures on microstructure of V2O5 films was studied by XRD and Raman scattering measurements. The results reveal that sputtered V2O5 films show preferred growth orientation along (001) planes and the c-axis is perpendicular to the silicon substrate surface. It is interesting to find that both the V2O5 film deposited at temperature of 511 ℃ and the one annealed at 500 ℃ exhibit desirable layer-type structure of orthorhombic symmetry. Such layer-typed V2O5 films are promising candidates for cathodes of rechargeable lithium or magnesium thin-film batteries.展开更多
Single crystalline calcium chloroborate（Ca2B5O9Cl） whiskers with uniform diameter have been fabricated by a two-step process. The precursor was firstly prepared by the sedimentation reaction between CaCl2, H3BO3 and...Single crystalline calcium chloroborate（Ca2B5O9Cl） whiskers with uniform diameter have been fabricated by a two-step process. The precursor was firstly prepared by the sedimentation reaction between CaCl2, H3BO3 and Na OH aqueous solutions, and then sintered at different temperatures for 6 h with KCl as flux. The XRD indicates that the product synthesized at 600 °C is Orthorhombic Ca2B5O9Cl. SEM and TEM results show that the Ca2B5O9Cl is whisker with the diameter about 0.2-0.5 μm and the length up to 15 μm. SAED analysis shows that the whisker is single crystalline and grows along [001] direction. The possible formation process and growth mechanism were proposed.展开更多
Y2O3 stabilized ZrO2(YSZ)thermal barrier coatings(TBCs)are prone to hot corrosion by molten salts.In this study,the microstructure of atmospheric plasma spraying YSZ TBCs is modified by laser glazing in order to impro...Y2O3 stabilized ZrO2(YSZ)thermal barrier coatings(TBCs)are prone to hot corrosion by molten salts.In this study,the microstructure of atmospheric plasma spraying YSZ TBCs is modified by laser glazing in order to improve the corrosion resistance.By optimizing the laser parameters,a^18μm smooth glazed layer with some vertical cracks was produced on the coating surfaces.The as-sprayed and modified coatings were both exposed to hot corrosion tests at 700 and 1000℃for 4 h in V2O5 molten salt,and the results revealed that the modified one had improved corrosion resistance.After hot corrosion,the glazed layer kept structural integrity,with little evidence of dissolution.However,the vertical cracks in the glazed layer acted as the paths for molten salt penetration,accelerating the corrosion of the non-modified coating.Further optimization of the glazed layer is needed in the future work.展开更多
文摘The microstructure of CaO-P_2O_5-SiO_2-MgO-F^- glass-ceramics duringcrystallization were investigated and the crystallized phases were identified with DTA (DifferentialThermal Analysis), SEM (Scanning Electron Microscope) and XRD (X- ray Diffraction) techniques. Themechanical properties such as bending strength and fracture toughness, as well as their changes withadvancing crystallization were determined. The results show that the changes of the mechanicalproperties are correlated with the microstructures. The sample heated up to 810 deg C and soaked for4 h has smaller crystalline size and less volum fraction of fluorophlogopite, so it has higherbending strength (about 190 MPa), and higher crack toughness (about 2.63 MPa centre dot m^1/2).
基金[This work was financially supported by the National Natural Science Foundation of China (No.50402024)Natural Science Foundation of Gansu Province (No.ZS 041-A25-033).
文摘V2O5 films were prepared on silicon wafers by DC magnetron sputtering and post-annealing under various conditions. The influence of depositing and post-annealing temperatures on microstructure of V2O5 films was studied by XRD and Raman scattering measurements. The results reveal that sputtered V2O5 films show preferred growth orientation along (001) planes and the c-axis is perpendicular to the silicon substrate surface. It is interesting to find that both the V2O5 film deposited at temperature of 511 ℃ and the one annealed at 500 ℃ exhibit desirable layer-type structure of orthorhombic symmetry. Such layer-typed V2O5 films are promising candidates for cathodes of rechargeable lithium or magnesium thin-film batteries.
基金Funded by the National Natural Science Foundation of China(No.51402323)the West Light Foundation of the Chinese Academy of Sciences(No.Y412031006)the Natural Science Foundation of Qinghai Province,China(No.2014-ZJ-938Q)
文摘Single crystalline calcium chloroborate（Ca2B5O9Cl） whiskers with uniform diameter have been fabricated by a two-step process. The precursor was firstly prepared by the sedimentation reaction between CaCl2, H3BO3 and Na OH aqueous solutions, and then sintered at different temperatures for 6 h with KCl as flux. The XRD indicates that the product synthesized at 600 °C is Orthorhombic Ca2B5O9Cl. SEM and TEM results show that the Ca2B5O9Cl is whisker with the diameter about 0.2-0.5 μm and the length up to 15 μm. SAED analysis shows that the whisker is single crystalline and grows along [001] direction. The possible formation process and growth mechanism were proposed.
基金This research is sponsored by the National Natural Science Foundation of China(Grant No.51971156).
文摘Y2O3 stabilized ZrO2(YSZ)thermal barrier coatings(TBCs)are prone to hot corrosion by molten salts.In this study,the microstructure of atmospheric plasma spraying YSZ TBCs is modified by laser glazing in order to improve the corrosion resistance.By optimizing the laser parameters,a^18μm smooth glazed layer with some vertical cracks was produced on the coating surfaces.The as-sprayed and modified coatings were both exposed to hot corrosion tests at 700 and 1000℃for 4 h in V2O5 molten salt,and the results revealed that the modified one had improved corrosion resistance.After hot corrosion,the glazed layer kept structural integrity,with little evidence of dissolution.However,the vertical cracks in the glazed layer acted as the paths for molten salt penetration,accelerating the corrosion of the non-modified coating.Further optimization of the glazed layer is needed in the future work.
