In this research,a novel method for regulating components in RE_(2)SiO_(5)/RE_(2)Si_(2)O_(7)multiphase silicates was developed,combining the benefits of a suitable thermal expansion coefficient(CTE)and outstanding cor...In this research,a novel method for regulating components in RE_(2)SiO_(5)/RE_(2)Si_(2)O_(7)multiphase silicates was developed,combining the benefits of a suitable thermal expansion coefficient(CTE)and outstanding corrosion resistance against calcium–magnesium–alumino–silicate(CMAS).This approach enhanced the overall thermophysical properties.Additionally,the results from the CMAS corrosion resistance test indicated that(Lu_(1/3)Yb_(1/3)Tm_(1/3))_(2)SiO_(5)/(Lu_(1/3)Yb_(1/3)Tm_(1/3))_(2)Si_(2)O_(7)and(Lu_(1/4)Yb_(1/4)Tm_(1/4)Er_(1/4))_(2)SiO_(5)/(Lu_(1/4)Yb_(1/4)Tm_(1/4)Er_(1/4))_(2)Si_(2)O_(7)exhibited exceptional resistance to CMAS penetration,even at temperatures up to 1500℃.To comprehend the corrosion mechanism of CMAS on these silicates,we introduced a reaction–diffusion model,which involved observing the changes in the interface between the corrosion product layer and the silicate block.This was achieved using electron backscatter diffraction(EBSD).These findings lay a theoretical basis for selecting rare earth elements in RE_(2)SiO_(5)/RE_(2)Si_(2)O_(7)multiphase silicates based on the radii of different rare earth cations.展开更多
In the rapidly evolving aerospace sector,the quest for sophisticated thermal barrier coating(TBC)materials has intensified.These materials are primarily sought for their superior comprehensive thermal characteristics,...In the rapidly evolving aerospace sector,the quest for sophisticated thermal barrier coating(TBC)materials has intensified.These materials are primarily sought for their superior comprehensive thermal characteristics,which include a low thermal conductivity coupled with a high coefficient of thermal expansion(CTE)that synergizes with the substrate.In our study,we adopt a solid-state method to synthesize a series of high-entropy rare-earth cerates:La_(2)Ce_(2)O_(7)(1RC),(La_(1/2)Nd_(1/2))2Ce_(2)O_(7)(2RC),(La_(1/3)Nd_(1/3)Sm_(1/3))_(2)Ce_(2)O_(7)(3RC),(La_(1/4)Nd_(1/4)Sm_(1/4)Eu_(1/4))_(2)Ce_(2)O_(7)(4RC),and(La_(1/5)Nd_(1/5)Sm_(1/5)Eu_(1/5)Gd_(1/5))_(2)Ce_(2)O_(7)(5RC),all sintered at 1,600℃ for 10 h.We thoroughly examine their phase structure,morphology,elemental distribution,and thermal properties.Our in-depth analysis of the phonon scattering mechanisms reveals that 4RC and 5RC exhibit exceptional thermal properties:high CTEs of 13.00×10^(−6) K^(−1) and 12.77×10^(−6) K^(−1) at 1,400℃,and low thermal conductivities of 1.55 W/(m·K)and 1.68 W/(m·K)at 1,000℃,respectively.Compared to other TBC systems,4RC and 5RC stand out for their excellent thermal characteristics.This study significantly contributes to the development of high-entropy oxides for TBC applications.展开更多
基金supported by the National Key R&D Program of China(No.2023YFF0719800).
文摘In this research,a novel method for regulating components in RE_(2)SiO_(5)/RE_(2)Si_(2)O_(7)multiphase silicates was developed,combining the benefits of a suitable thermal expansion coefficient(CTE)and outstanding corrosion resistance against calcium–magnesium–alumino–silicate(CMAS).This approach enhanced the overall thermophysical properties.Additionally,the results from the CMAS corrosion resistance test indicated that(Lu_(1/3)Yb_(1/3)Tm_(1/3))_(2)SiO_(5)/(Lu_(1/3)Yb_(1/3)Tm_(1/3))_(2)Si_(2)O_(7)and(Lu_(1/4)Yb_(1/4)Tm_(1/4)Er_(1/4))_(2)SiO_(5)/(Lu_(1/4)Yb_(1/4)Tm_(1/4)Er_(1/4))_(2)Si_(2)O_(7)exhibited exceptional resistance to CMAS penetration,even at temperatures up to 1500℃.To comprehend the corrosion mechanism of CMAS on these silicates,we introduced a reaction–diffusion model,which involved observing the changes in the interface between the corrosion product layer and the silicate block.This was achieved using electron backscatter diffraction(EBSD).These findings lay a theoretical basis for selecting rare earth elements in RE_(2)SiO_(5)/RE_(2)Si_(2)O_(7)multiphase silicates based on the radii of different rare earth cations.
基金This work was supported by the Instrument and equipment development,Chinese Academy of Sciences[YJKYYQ20210030]Shanghai Science and Technology Innovation Action Plan[21142201100].
文摘In the rapidly evolving aerospace sector,the quest for sophisticated thermal barrier coating(TBC)materials has intensified.These materials are primarily sought for their superior comprehensive thermal characteristics,which include a low thermal conductivity coupled with a high coefficient of thermal expansion(CTE)that synergizes with the substrate.In our study,we adopt a solid-state method to synthesize a series of high-entropy rare-earth cerates:La_(2)Ce_(2)O_(7)(1RC),(La_(1/2)Nd_(1/2))2Ce_(2)O_(7)(2RC),(La_(1/3)Nd_(1/3)Sm_(1/3))_(2)Ce_(2)O_(7)(3RC),(La_(1/4)Nd_(1/4)Sm_(1/4)Eu_(1/4))_(2)Ce_(2)O_(7)(4RC),and(La_(1/5)Nd_(1/5)Sm_(1/5)Eu_(1/5)Gd_(1/5))_(2)Ce_(2)O_(7)(5RC),all sintered at 1,600℃ for 10 h.We thoroughly examine their phase structure,morphology,elemental distribution,and thermal properties.Our in-depth analysis of the phonon scattering mechanisms reveals that 4RC and 5RC exhibit exceptional thermal properties:high CTEs of 13.00×10^(−6) K^(−1) and 12.77×10^(−6) K^(−1) at 1,400℃,and low thermal conductivities of 1.55 W/(m·K)and 1.68 W/(m·K)at 1,000℃,respectively.Compared to other TBC systems,4RC and 5RC stand out for their excellent thermal characteristics.This study significantly contributes to the development of high-entropy oxides for TBC applications.
