An X-ray diffraction investigation of infinity-Al2O3 addition to yttria stabilized zirconia (YSZ) thermal barrier coatings subject to destabilizing vanadium pentoxide (V2O5) exposure

Abstract

Since the mid 1970's the U.S. Navy has used Yttria-stabilized zirconia ( YSZ ) as thermal barrier coatings for hot stage gas turbine components. Use of low cost, high contaminant, fuels has led to shortened component life from failure of YSZ coatings due to corrosive attack by vanadium and other combustion oxides. The object of this investigation was to determine the reactivity of adding alpha-Al203 to Current YSZ ceramics for creation of a ceramic composite which could improve mechanical properties and show improved durability to corrosive chemical attack. Ten powder samples of Zro2(8)Mol%YzO3, alpha-Al2O3, and V20s5 of varying compositions were annealed at 900 deg C for 100 hours. X-Ray Diffraction analysis utilizing a standard 'search and match' method was used to determine the phases present in the reacted powder samples. Peak intensity comparisons between reacted and un-reacted samples allowed for a quantitative determination for the reactivity of a-A1203 with the YSZ system exposed to V2O3. This investigation indicated that alpha-Al2O3 is non-reactive in all YSZ samples exposed to V205 at 900 deg C. Ceramic, Alpha alumina, YSZ, Vanadia, Surface-induced coating (SIC), PSZ, XRD, SEM