摘要
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.
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)
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)。
