Magnesia-stabilized zirconia (MSZ) thermal barrier coatings by suspension plasma spraying: Coating properties and service life behavior

Abstract

Magnesia-stabilized zirconia (MSZ) coatings have low thermal conductivity and a high melting point. Currently, they are only indicated for use at lower temperatures than well-established yttria-stabilized zirconia (YSZ) coatings. This study investigated the life behavior of MSZ TBCs. The TBCs were prepared using two thermal spray technologies: atmospheric plasma spray (APS) and suspension plasma spray (SPS). The NiCoCrAlHfSi bond coat was pre-oxidized. The double-layer system, consisting of an APS intermediate layer of yttria-stabilized zirconia (YSZ) and an SPS top layer of MSZ, outperformed the single-layer MSZ APS and MSZ SPS pre-oxidized coatings. These results suggest that multi-layer coatings have the potential to improve MSZ coating performance. The influence of low-content titania doping was also investigated; however, no significant effect on the performance of the coatings was observed.