Exploring superior calcium-magnesium-aluminosilicate(CMAS)corrosion resistance is crucial for highentropy rare-earth monosilicates(HEREMs)as the next-generation environmental barrier coating(EBC)materials.However,rela...Exploring superior calcium-magnesium-aluminosilicate(CMAS)corrosion resistance is crucial for highentropy rare-earth monosilicates(HEREMs)as the next-generation environmental barrier coating(EBC)materials.However,related studies are rarely reported.This work presents the exploration of HEREMs with remarkable CMAS corrosion resistance by engineering their compositions.The equimolar 3-to-9 cation high-entropy rare-earth monosilicate(3-9HEREM)specimens were initially prepared using a pressure-less sintering technique;subsequently,their resistance to CMAS corrosion was evaluated at temperatures up to 1600C.The results demonstrate that the 5HEREM specimens possess the best CMAS corrosion resistance among all the as-fabricated specimens,surpassing other reported EBC materials.Such remarkable CMAS corrosion resistance results from the generation of a dense apatite protective layer originating from its low dissolution rate at elevated temperatures.展开更多
Herein we establish formation ability descriptors of high-entropy rare-earth monosilicates(HEREMs)via the data-driven discovery based on the high-throughput solid-state reaction and machine learning(ML)methods.Specifi...Herein we establish formation ability descriptors of high-entropy rare-earth monosilicates(HEREMs)via the data-driven discovery based on the high-throughput solid-state reaction and machine learning(ML)methods.Specifically,adequate high-quality data are generated with 132 samples synthesized by the self-developed high-throughput solid-state reaction apparatuses,and 30 potential descriptors are considered in ML simultaneously.Two classifications are proposed to study the phase formation of HEREMs via the ML approach combined with the genetic algorithm:(Ⅰ)to distinguish pure HEREMs(X)from other phases and(Ⅱ)to categorize the detail phases of HEREMs(X2,X1,or X2+X1).Four formation ability descriptors(r_(Me),EF,d_(Eg),and d_(Z*))with a high validation accuracy(96.2%)are proposed as the optimal combination for Classification I,where a smaller r_(Me)is determined to have the most significant influence on the formation of HEREMs.For ClassificationⅡ,a 100%validation accuracy is achieved by using only two formation ability descriptors(rion and d_(Z*)),where the rion is analyzed to be the dominant feature and a lower rion is beneficial to the formation of X2-HEREMs.Based on our established formation ability descriptors,6,045 unreported multicomponent silicates are explored,and 3,478 new HEREMs with 2,700 X2-and 423 X1-HEREMs are predicted.展开更多
A novel high entropy(HE) rare earth monosilicate(Yb0.25Y0.25Lu0.25Er0.252 SiO5 was synthesized by solid-state reaction method.X-ray diffraction and scanning electron microscopy analysis indicate that a single solid so...A novel high entropy(HE) rare earth monosilicate(Yb0.25Y0.25Lu0.25Er0.252 SiO5 was synthesized by solid-state reaction method.X-ray diffraction and scanning electron microscopy analysis indicate that a single solid solution is formed with homogeneous distribution of rare-earth elements.HE(Yb0.25Y0.25Lu0.255 Er0.252 SiO5 exhibits excellent phase stability and anisotropy in thermal expansion.The coefficients of thermal expansion(CTEs) in three crystallographic directions are:αa=(2.57±0.07)×10^-6 K^-1,αb=(8.07±0.13)×10^-6 K^-1,αc=(9.98±0.10)×10^-6 K^-1.The strong anisotropy in thermal expansion is favorable in minimizing the coating/substrate mismatch if preferred orientation of HE(Yb0.25Y0.25Lu0.25Er0.252 SiO5 is controlled on either metal or ceramic substrate.展开更多
In this work,the microstructure evolution,thermal expansion,thermal conductivity,and thermal shock resistance properties of the plasma-sprayed Xl-Gd_(2)SiO_(5),X2-Y_(2)SiO_(5),and X2-Er_(2)SiO_(5)coatings were evaluat...In this work,the microstructure evolution,thermal expansion,thermal conductivity,and thermal shock resistance properties of the plasma-sprayed Xl-Gd_(2)SiO_(5),X2-Y_(2)SiO_(5),and X2-Er_(2)SiO_(5)coatings were evaluated and compared by experimental measurement and theoretical exploration.Results showed that significant microstructure evolution such as crystallization of amorphous phase,grain growth,and defects reduction was observed in the RE_(2)SiO_(5)coatings after thermal aging at 1400℃.The Xl-Gd_(2)SiO_(5)coating exhibited higher CTE values than the X2-Y_(2)SiO_(5)and X2-Er_(2)SiO_(5)coatings,which was related to their crystal structure.The thermal conductivity of thermal-aged RE_(2)SiO_(5)coating was much higher than that of the as-sprayed RE_(2)SiO_(5)coating,and thermal conductivity was determined not only by crystal structure but also mainly by the microstructure of the coatings.The X2-Y_(2)SiO_(5)and X2-Er_(2)SiO_(5)coatings with lower thermal mismatch stre s ses presented much better thermal shock resistance than the X1-Gd_(2)SiO_(5)coating.展开更多
基金the National Key Research and Development Program of China(No.2022YFB3708600)the National Natural Science Foundation of China(No.52122204).
文摘Exploring superior calcium-magnesium-aluminosilicate(CMAS)corrosion resistance is crucial for highentropy rare-earth monosilicates(HEREMs)as the next-generation environmental barrier coating(EBC)materials.However,related studies are rarely reported.This work presents the exploration of HEREMs with remarkable CMAS corrosion resistance by engineering their compositions.The equimolar 3-to-9 cation high-entropy rare-earth monosilicate(3-9HEREM)specimens were initially prepared using a pressure-less sintering technique;subsequently,their resistance to CMAS corrosion was evaluated at temperatures up to 1600C.The results demonstrate that the 5HEREM specimens possess the best CMAS corrosion resistance among all the as-fabricated specimens,surpassing other reported EBC materials.Such remarkable CMAS corrosion resistance results from the generation of a dense apatite protective layer originating from its low dissolution rate at elevated temperatures.
基金support from the National Key Research and Development Program of China(No.2022YFB3708600)the National Natural Science Foundation of China(No.52122204 and 51972116)Guangzhou Basic and Applied Basic Research Foundation(No.202201010632).
文摘Herein we establish formation ability descriptors of high-entropy rare-earth monosilicates(HEREMs)via the data-driven discovery based on the high-throughput solid-state reaction and machine learning(ML)methods.Specifically,adequate high-quality data are generated with 132 samples synthesized by the self-developed high-throughput solid-state reaction apparatuses,and 30 potential descriptors are considered in ML simultaneously.Two classifications are proposed to study the phase formation of HEREMs via the ML approach combined with the genetic algorithm:(Ⅰ)to distinguish pure HEREMs(X)from other phases and(Ⅱ)to categorize the detail phases of HEREMs(X2,X1,or X2+X1).Four formation ability descriptors(r_(Me),EF,d_(Eg),and d_(Z*))with a high validation accuracy(96.2%)are proposed as the optimal combination for Classification I,where a smaller r_(Me)is determined to have the most significant influence on the formation of HEREMs.For ClassificationⅡ,a 100%validation accuracy is achieved by using only two formation ability descriptors(rion and d_(Z*)),where the rion is analyzed to be the dominant feature and a lower rion is beneficial to the formation of X2-HEREMs.Based on our established formation ability descriptors,6,045 unreported multicomponent silicates are explored,and 3,478 new HEREMs with 2,700 X2-and 423 X1-HEREMs are predicted.
基金financially supported by the National Natural Science Foundation of China(Nos.51672064andU1435206)。
文摘A novel high entropy(HE) rare earth monosilicate(Yb0.25Y0.25Lu0.25Er0.252 SiO5 was synthesized by solid-state reaction method.X-ray diffraction and scanning electron microscopy analysis indicate that a single solid solution is formed with homogeneous distribution of rare-earth elements.HE(Yb0.25Y0.25Lu0.255 Er0.252 SiO5 exhibits excellent phase stability and anisotropy in thermal expansion.The coefficients of thermal expansion(CTEs) in three crystallographic directions are:αa=(2.57±0.07)×10^-6 K^-1,αb=(8.07±0.13)×10^-6 K^-1,αc=(9.98±0.10)×10^-6 K^-1.The strong anisotropy in thermal expansion is favorable in minimizing the coating/substrate mismatch if preferred orientation of HE(Yb0.25Y0.25Lu0.25Er0.252 SiO5 is controlled on either metal or ceramic substrate.
基金financially supported by the National Key R&D Program of China(No.2018YFB0704400)the National Science and Technology Major Project(No.2017-VI-0020-0092)+2 种基金the Shanghai Technical Platform for Testing on Inorganic Materials(No.19DZ2290700)the Shanghai Sailing Program(No.19YF1453900)the Natural Science Foundation of Shanghai(No.20ZR1465700)。
文摘In this work,the microstructure evolution,thermal expansion,thermal conductivity,and thermal shock resistance properties of the plasma-sprayed Xl-Gd_(2)SiO_(5),X2-Y_(2)SiO_(5),and X2-Er_(2)SiO_(5)coatings were evaluated and compared by experimental measurement and theoretical exploration.Results showed that significant microstructure evolution such as crystallization of amorphous phase,grain growth,and defects reduction was observed in the RE_(2)SiO_(5)coatings after thermal aging at 1400℃.The Xl-Gd_(2)SiO_(5)coating exhibited higher CTE values than the X2-Y_(2)SiO_(5)and X2-Er_(2)SiO_(5)coatings,which was related to their crystal structure.The thermal conductivity of thermal-aged RE_(2)SiO_(5)coating was much higher than that of the as-sprayed RE_(2)SiO_(5)coating,and thermal conductivity was determined not only by crystal structure but also mainly by the microstructure of the coatings.The X2-Y_(2)SiO_(5)and X2-Er_(2)SiO_(5)coatings with lower thermal mismatch stre s ses presented much better thermal shock resistance than the X1-Gd_(2)SiO_(5)coating.
