Model On Thermal Conductivity Prediction Of Quasi-Columnar Structured Coating By Plasma Spray Physical Vapor Deposition

Firstly, the yttria-stabilized zirconia (YSZ) coating and gadolinium zirconate (GZO) coating with the quasicolumnar structure were manufactured by plasma spray physical vapor deposition. At the same time, a novel three-dimensional geometrical model was established that could satisfactorily reflect such quasi-columnar structural characteristics. Then, based on this model, the three-dimensional spatial distribution of pores and porosity of coatings and the thermal resistance behaviors of the quasi-columnar structured coating were analyzed. Later on, the thermodynamic model was established to estimate the thermal conductivity of the quasicolumnar structured coatings at different temperatures. Finally, a model for predicting the effective thermal conductivity of the GZO/YSZ double-layer coating with quasi-columnar structure was validated to account for the effects of the variable thickness ratios of GZO top layer to YSZ inner layer.