Impact of bond coat types on calcium-magnesium-alumina-silicate and hot corrosion behavior in thermal barrier coatings

This study examines the corrosion behavior of thermal barrier coatings (TBCs) with bond coats (BCs) fabricated using Air plasma spraying (APS) and High velocity oxygen fuel (HVOF) against molten salt and Calciummagnesium-alumina-silicate (CMAS) corrosion. Results show that TBCs with the APS-BC have higher resistance and experience fewer failures than those with the HVOF-BC due to the further growth of the aluminum-rich oxide layer in APS-BC coatings, causing the salt to be neutralized during the reaction with BC. The products of the reaction between CMAS and TGO lead to changes in coating interface morphology and degradation in coatings with HVOF BC.