Novel thermal barrier coatings based on Mg2SiO4/8YSZ double-ceramic-layer systems deposited by APS

Abstract

Novel thermal barrier coatings (TBCs) based on Mg 2 SiO 4 /8YSZ double-ceramic-layer (DCL) were prepared by atmospheric plasma spraying (APS). Thermal cycling tests of the TBC specimens were performed at 1373 K. Results indicate that the DCL coating has a much longer lifetime compared to the single layer Mg 2 SiO 4 coating. This is attributed to the fact that DCL Mg 2 SiO 4 /8YSZ TBCs further enhances the thermal insulation effect, improves sintering resistance and relieves thermal mismatch between ceramic layer and bond coat (BC). It can be concluded that this DCL coating structure design is ideal to optimize the performance of single layer Mg 2 SiO 4 TBC and shows the Mg 2 SiO 4 exhibiting a promising potential as new TBC materials. • The DCL coating has a much longer thermal cycling lifetime than that of the single layer coating of Mg 2 SiO 4 . • The designed DCL coating system is helpful to prolong the thermal cycling life. • The failure mechanism of DCL coating was studied.