Excellent sintering resistance of zirconia-based bi-phase solid solution ceramic coating

The microstructure and sintering behavior of zirconia-based bi-phase solid solution (BPS) ceramic coating prepared by air plasma spraying have been investigated. It is found that the BPS coating is composed of cubic and tetragonal phases, which are well-adhered. During the 1200 °C thermal cycling, the densification of intersplat pores and cracks is inhibited due to the differential sintering of nano-grains and the high density of oxygen ions located in the crystal plane. The average grain diameter and Young’s modulus are reduced, and the thermal conductivity is maintained at a constant level after 250 thermal cycles. The sintering resistance of BPS coating is 40 % higher than 8YSZ coating. [Display omitted] •Cubic and tetragonal phases are well-adhered in bi-phase solid solution coating.•Densification of fracture surfaces in bi-phase solid solution coating are inhibited.•Increase of Young’s modulus and thermal conductivity is retarded in BPS coating.•Sintering resistance of BPS coating is 40 % higher than 8YSZ.