Sintered plates of 5mol% yttria-partially-stabilized zirconia have been implanted at room temperature with 5 ×1015to 2 ×1017 Fe+ ions/cm2 at 140 KeV. Electrical measurement, Rutherford backscattering spec-tr...Sintered plates of 5mol% yttria-partially-stabilized zirconia have been implanted at room temperature with 5 ×1015to 2 ×1017 Fe+ ions/cm2 at 140 KeV. Electrical measurement, Rutherford backscattering spec-troscopy(RBS), Raman spectroscopy and X-ray photoelec-tron spectroscopy(XPS) have been used to study the surface electrical properties and the structure of the implanted layer before and after thermal annealing treatment in N2.展开更多
Ni-Al2O3 cermet supported tubular SOFC was fabricated by thermal spraying. Flame-sprayed Al2O3-Ni cermet coating plays dual roles of a support tube and an anode current collector. 4.5mol.% yttria-stabilized zirconia (...Ni-Al2O3 cermet supported tubular SOFC was fabricated by thermal spraying. Flame-sprayed Al2O3-Ni cermet coating plays dual roles of a support tube and an anode current collector. 4.5mol.% yttria-stabilized zirconia (YSZ) and 10mol.% scandia-stabilized zirconia (ScSZ) coatings were deposited by atmospheric plasma spraying (APS) as the electrolyte in present study. The electrical conductivity of electrolyte was measured using DC method. The post treatment was employed using nitrate solution infiltration to densify APS electrolyte layer for improvement of gas permeability. The electrical conductivity of electrolyte and the performance of single cell were investigated to optimize SOFC performance. The electrical conductivity of the as-sprayed YSZ and ScSZ coating is about 0.03 and 0.07 S·cm-1 at 1000 ℃, respectively. The ohmic polarization significantly influences the performance of SOFC. The maximum output power density at 1000 ℃ increases from 0.47 to 0.76 W·cm-2 as the YSZ electrolyte thickness reduces from 100 μm to 40 μm. Using APS ScSZ coating of about 40 μm as the electrolyte, the test cell presents a maximum power output density of over 0.89 W·cm-2 at 1000 ℃.展开更多
Yttria stabilized zirconia(YSZ)film has been screen printed and sintered on a rigid substrate.The constrained sintering caused the formation of multiple microcracks and most critically large“blister”defects.The morp...Yttria stabilized zirconia(YSZ)film has been screen printed and sintered on a rigid substrate.The constrained sintering caused the formation of multiple microcracks and most critically large“blister”defects.The morphology of such defects has been characterized by scanning electron microscopy(SEM).It was revealed that the film surface exhibits noticeable roughness.Microhardness testing revealed little variation in green density distribution.Rheological measurement,however,showed that some agglomerations are present in the YSZ ink.The existence of agglomerations in the screen printing ink in combination with debonding at the film/substrate interface is potentially the cause for the formation of blister defects.展开更多
The yttria-stabilized zirconia(YSZ)film was fabricated on the La 0.8 Sr 0.2 MnO 3(LSM)substrate by electrochemical deposition.The effects of electrochemical deposition conditions on morphological structure of Y(OH) 3 ...The yttria-stabilized zirconia(YSZ)film was fabricated on the La 0.8 Sr 0.2 MnO 3(LSM)substrate by electrochemical deposition.The effects of electrochemical deposition conditions on morphological structure of Y(OH) 3 -Zr(OH) 4 film were studied.The optimal conditions for depositing homogeneous and compact hydroxide film were obtained.The experimental results show that the density of the electrophoretic deposition film is increased remarkably if electrochemical deposition is applied to fill in the pores.展开更多
Thermal barrier coatings （TBCs） with Y2O3-stabilized ZrO2 （YSZ） top coat play a very important role in advanced turbine blades by considerably increasing the engine efficiency and improving the performance of high...Thermal barrier coatings （TBCs） with Y2O3-stabilized ZrO2 （YSZ） top coat play a very important role in advanced turbine blades by considerably increasing the engine efficiency and improving the performance of highly loaded blades. However, at high temperatures, environment factors result in the failure of TBCs. The influence of calcium-magnesium-alumino-silicate （CMAS） is one of environment factors. Although thermo-physical effect is being paid attention to, the thermo-chemical reaction becomes the hot-spot in the research area of TBCs affected by CMAS. In this paper, traditional twolayered structured TBCs were prepared by electron beam physical vapor deposition （EB- PVD） as the object of study. TBCs coated with CMAS were heated at 1240℃ for 3 h. Additionally, 15 wt.% simulated molten CMAS powder and YSZ powder were mixed and heated at 1240℃ or 1350℃ for 48 h. SEM and EDS were adopted to detect morphology and elements distribution. According to XRD and TEM results, it was revealed that CMAS react with YSZ at high temperature and form ZrSiO4, Ca0.2Zr0.8O1.8 and Ca0.15Zr0.85O1.85 after reaction, as a result, leading to the failure of TBCs and decreasing the TBC lifetime.展开更多
文摘Sintered plates of 5mol% yttria-partially-stabilized zirconia have been implanted at room temperature with 5 ×1015to 2 ×1017 Fe+ ions/cm2 at 140 KeV. Electrical measurement, Rutherford backscattering spec-troscopy(RBS), Raman spectroscopy and X-ray photoelec-tron spectroscopy(XPS) have been used to study the surface electrical properties and the structure of the implanted layer before and after thermal annealing treatment in N2.
基金The present project was supported by Foundation of China Education Ministry for Talented Young Scholar, Education Promotion Project and Doctoral Thesis Foundation of Xi'an Jiaotong University.
文摘Ni-Al2O3 cermet supported tubular SOFC was fabricated by thermal spraying. Flame-sprayed Al2O3-Ni cermet coating plays dual roles of a support tube and an anode current collector. 4.5mol.% yttria-stabilized zirconia (YSZ) and 10mol.% scandia-stabilized zirconia (ScSZ) coatings were deposited by atmospheric plasma spraying (APS) as the electrolyte in present study. The electrical conductivity of electrolyte was measured using DC method. The post treatment was employed using nitrate solution infiltration to densify APS electrolyte layer for improvement of gas permeability. The electrical conductivity of electrolyte and the performance of single cell were investigated to optimize SOFC performance. The electrical conductivity of the as-sprayed YSZ and ScSZ coating is about 0.03 and 0.07 S·cm-1 at 1000 ℃, respectively. The ohmic polarization significantly influences the performance of SOFC. The maximum output power density at 1000 ℃ increases from 0.47 to 0.76 W·cm-2 as the YSZ electrolyte thickness reduces from 100 μm to 40 μm. Using APS ScSZ coating of about 40 μm as the electrolyte, the test cell presents a maximum power output density of over 0.89 W·cm-2 at 1000 ℃.
文摘Yttria stabilized zirconia(YSZ)film has been screen printed and sintered on a rigid substrate.The constrained sintering caused the formation of multiple microcracks and most critically large“blister”defects.The morphology of such defects has been characterized by scanning electron microscopy(SEM).It was revealed that the film surface exhibits noticeable roughness.Microhardness testing revealed little variation in green density distribution.Rheological measurement,however,showed that some agglomerations are present in the YSZ ink.The existence of agglomerations in the screen printing ink in combination with debonding at the film/substrate interface is potentially the cause for the formation of blister defects.
文摘The yttria-stabilized zirconia(YSZ)film was fabricated on the La 0.8 Sr 0.2 MnO 3(LSM)substrate by electrochemical deposition.The effects of electrochemical deposition conditions on morphological structure of Y(OH) 3 -Zr(OH) 4 film were studied.The optimal conditions for depositing homogeneous and compact hydroxide film were obtained.The experimental results show that the density of the electrophoretic deposition film is increased remarkably if electrochemical deposition is applied to fill in the pores.
文摘Thermal barrier coatings （TBCs） with Y2O3-stabilized ZrO2 （YSZ） top coat play a very important role in advanced turbine blades by considerably increasing the engine efficiency and improving the performance of highly loaded blades. However, at high temperatures, environment factors result in the failure of TBCs. The influence of calcium-magnesium-alumino-silicate （CMAS） is one of environment factors. Although thermo-physical effect is being paid attention to, the thermo-chemical reaction becomes the hot-spot in the research area of TBCs affected by CMAS. In this paper, traditional twolayered structured TBCs were prepared by electron beam physical vapor deposition （EB- PVD） as the object of study. TBCs coated with CMAS were heated at 1240℃ for 3 h. Additionally, 15 wt.% simulated molten CMAS powder and YSZ powder were mixed and heated at 1240℃ or 1350℃ for 48 h. SEM and EDS were adopted to detect morphology and elements distribution. According to XRD and TEM results, it was revealed that CMAS react with YSZ at high temperature and form ZrSiO4, Ca0.2Zr0.8O1.8 and Ca0.15Zr0.85O1.85 after reaction, as a result, leading to the failure of TBCs and decreasing the TBC lifetime.
