Abstract: Si/(Yb1-xYx)2Si2O7/LaMgAl11O19(x=0, 0.5) thermal/environmental barrier coatings (T/EBCs) were prepared by plasma sprayingmethod on the surface of SiC fiber reinforced SiC ceramic composites (SiCf/SiC-CMCs). The thermal cycle performance and water-oxygen corrosion resistance at 1 300 ℃ of T/EBCs systems with different components were investigated by means of SEM, EDS and XRD. And failure mechanisms of the thermal cycle and water-oxygen corrosion were further discussed. The results indicate that the thermal cycle life of Si/Yb2Si2O7/LMA coating system is 403 cycles and water-oxygen corrosion resistance is 50 h. The thermal cycle life of Si/YbYSi2O7/LMA system decreases to 277 cycles, while the water-oxygen corrosion resistance increases to 80 h. The larger thermal mismatch stress and the formation of Al-containing compounds or solid solutions between YbYSi2O7 and LMA are the main factors that reduce the thermal cycle life of Si/YbYSi2O7/LMA. The less oxide impurities in the YbYSi2O7-EBC layer reduce the probability of reaction with water to generate volatile substances, and improve the water-oxygen corrosion resistance of Si/YbYSi2O7/LMA.
Key words: SiCf/SiC-CMCs, thermal/environmental barrier coating, thermal barrier coating, environmental barrier coating, thermal cycle, high temperature water-oxygen corrosion, Yb2Si2O7, YbYSi2O7
Declaration: This article is provided by CERADIR™ users or obtained from Internet, the content does not represent the position of CERADIR™. We are not responsible for the authenticity/accuracy of the article, especially the effects of the products concerned. This article is for study only, it does not constitute any investment or application advice. For reprinting, please contact the original author. If it involves the copyright and/or other issues, please contact us and we will deal with it asap! CERADIR™ has the interpretation of this declaration.
