The corrosion resistance characteristics of RE-rich RE_(50)Ta_(x)Zr_(50-x)O_(175+0.5x)oxides in RE_(2)Zr_(2)O_(7)-RETaO_(4)systems to calcium-magnesium-alumino-silicate(CMAS)at 1300°C,and the influence of RE^(3+)...The corrosion resistance characteristics of RE-rich RE_(50)Ta_(x)Zr_(50-x)O_(175+0.5x)oxides in RE_(2)Zr_(2)O_(7)-RETaO_(4)systems to calcium-magnesium-alumino-silicate(CMAS)at 1300°C,and the influence of RE^(3+)and Ta^(5+)on chemical reactions and reactive crystallization of CMAS melts were investigated.The results show that following the thermochemical reactions,apatite,pyrochlore,reprecipitated fluorite and residual Yb(Y)TaO4phases were the predominant reaction products.Formation abilities of apatite and pyrochlore were found to be proportional to the ionic radius of RE^(3+).The increase of Ta^(5+)amount can decrease the number of available RE^(3+)to form apatite.Moreover,the resistance characteristic to CMAS corrosion in RE_(50)Ta_(x)Zr_(50-x)O_(175+0.5x)systems was decided by the combined action of apatite and pyrochlore phases.The cohesive mixture of apatite and pyrochlore phases can generate a dense layer near the reaction front,which had a positive effect on suppressing CMAS infiltration.The ability of the fluorite+RETaO4two-phase field was determined to be sufficient to mitigate CMAS corrosion.展开更多
The corrosion of metals or alloys under solid NaCl deposit in wet oxygen （water vapor and oxygen） at medium temperature 4013-700℃ causes serious damage and has received considerable attention in recent years. Serie...The corrosion of metals or alloys under solid NaCl deposit in wet oxygen （water vapor and oxygen） at medium temperature 4013-700℃ causes serious damage and has received considerable attention in recent years. Series of mechanistic studies have revealed synergistic interactions between solid NaCl and water vapor, which accelerates the corrosion process. In addition, the overall corrosion process comprises both chemical reactions （oxidation） and electrochemical reactions and their mutual inter- actions depend on the system of interest. Interestingly, the wet oxygen environment was found to modify the reactions of the element Cr, which plays a useful role in corrosion protection in this special environment.展开更多
基金supported by the National Natural Science Foundation of China(No.51801170)the National Postdoctoral Program for Innovative Talents,China(No.BX20180265)+2 种基金the Natural Science Foundation of Hunan Province,China(No.2019JJ50570)the China Postdoctoral Science Foundation(No.2019M652786)the Research Initiation Project of Xiangtan University,China(No.18QDZ24)。
文摘The corrosion resistance characteristics of RE-rich RE_(50)Ta_(x)Zr_(50-x)O_(175+0.5x)oxides in RE_(2)Zr_(2)O_(7)-RETaO_(4)systems to calcium-magnesium-alumino-silicate(CMAS)at 1300°C,and the influence of RE^(3+)and Ta^(5+)on chemical reactions and reactive crystallization of CMAS melts were investigated.The results show that following the thermochemical reactions,apatite,pyrochlore,reprecipitated fluorite and residual Yb(Y)TaO4phases were the predominant reaction products.Formation abilities of apatite and pyrochlore were found to be proportional to the ionic radius of RE^(3+).The increase of Ta^(5+)amount can decrease the number of available RE^(3+)to form apatite.Moreover,the resistance characteristic to CMAS corrosion in RE_(50)Ta_(x)Zr_(50-x)O_(175+0.5x)systems was decided by the combined action of apatite and pyrochlore phases.The cohesive mixture of apatite and pyrochlore phases can generate a dense layer near the reaction front,which had a positive effect on suppressing CMAS infiltration.The ability of the fluorite+RETaO4two-phase field was determined to be sufficient to mitigate CMAS corrosion.
基金supported by the National Natural Science Fundation of China (Grant Nos. 50671113 and 50801063)
文摘The corrosion of metals or alloys under solid NaCl deposit in wet oxygen （water vapor and oxygen） at medium temperature 4013-700℃ causes serious damage and has received considerable attention in recent years. Series of mechanistic studies have revealed synergistic interactions between solid NaCl and water vapor, which accelerates the corrosion process. In addition, the overall corrosion process comprises both chemical reactions （oxidation） and electrochemical reactions and their mutual inter- actions depend on the system of interest. Interestingly, the wet oxygen environment was found to modify the reactions of the element Cr, which plays a useful role in corrosion protection in this special environment.
