Novel thermal barrier coatings with hexagonal boron nitride additives resistant to molten volcanic ash wetting

Abstract Yttria-stabilized zirconia thermal barrier coatings (YSZ TBCs) are prone to degradation by atmospheric contaminants such as volcanic ash, posing a serious threat to their durability. Here we demonstrate that hexagonal boron nitride (h-BN) additives to YSZ coatings (h-BN YSZ), exhibit resistance against volcanic ash interaction at 1250 °C. In preliminary tests performed under vacuum, h-BN YSZ coatings demonstrate greatly inhibited wetting against molten volcanic ash drops. Under oxidizing conditions, h-BN YSZ provide enhanced wetting and chemical resistance over conventional coatings. This study lays groundwork for the development of novel additives which are physico-chemically resilient against molten volcanic ash wetting.