Adsorbability and spreadability of calcium-magnesium-alumino-silicate (CMAS) on Al-modified 7YSZ thermal barrier coating

Abstract A dense α-Al 2 O 3 overlay was in-situ synthesized on 7YSZ TBC to mitigate the CMAS attack. The adsorbability and spreadability of CMAS on as-sprayed and Al-modified TBCs were investigated. The results show that compared to the as-spared TBC, the Al-modified TBC has lower adsorption mass and smaller spreading area. When the Al-modified 7YSZ coating was subjected to CMAS attack, the presence of large amounts of Al 2 O 3 will accelerate the formation of MgAl 2 O 4 spinel and induce the generation of CaAl 2 O 4 spinel apart from gehlenite Ca 2 Al 2 SiO 7 . Therefore, it can be concluded that Al-modified 7YSZ TBC has better CMAS corrosion resistance than as-sprayed TBC.