CMAS corrosion and thermal cycle of Al-modified PS-PVD environmental barrier coating

Abstract Environmental barrier coatings (EBCs) with a tri-layer structure consisting of silicon, mulltite and Yb 2 SiO 5 were deposited by plasma spray-physical vapor deposition (PS-PVD) on SiC/SiC ceramic matrix composite (CMC). To improve the calcium-aluminum-magnesium-silicates (CMAS) corrosion resistance of EBCs, a novel method called “Al-modification of EBCs surface” was proposed, wherein an Al film was first deposited on surface of Yb 2 SiO 5 top coating by magnetron sputtering, and afterwards the vacuum heat treatment was carried out on the Al-deposited EBCs samples. The thermal cycle performance of both as-sprayed and Al-modified EBCs was characterized from 1300 °C to the temperature of environmental water. Moreover, the CMAS corrosion property of both types of EBCs at 1300 °C has been compared with each other. And the corrosion mechanism between CMAS and Al-modified EBCs has been investigated. The results show that the Al-modified EBCs have a better thermal cycle and CMAS corrosion performance than that of as-sprayed EBCs.