Thermal conductivity of ZrO2-4 mol%Y2O3 thin coatings by pulsed thermal imaging method

• Thin ZrO2-4 mol% Y2O3 coatings were deposited by Electron Beam-Physical Vapor Deposition.
• ZrO2-4 mol% Y2O3 coatings revealed a feather-like columnar microstructure.
• The thermal conductivity was evaluated from double layers using the thermal image method.
• The thermal conductivity of coatings increased with increasing coating thickness.

Thin ZrO2-4 mol% Y2O3 coatings were deposited onto ZrO2 substrates by electron beam-physical vapor deposition. The coated samples revealed a feather-like columnar microstructure. The main phase of the ZrO2-4 mol% Y2O3 coatings was the tetragonal phase. To evaluate the influence of the coating's thickness on the thermal conductivity of thin ZrO2-4 mol% Y2O3 coatings, the pulsed thermal imaging method was employed to obtain the thermal conductivity of the coating layer in the two-layer (coating and substrate) samples with thickness between 56 and 337 μm. The thermal conductivity of the coating layer was successfully evaluated and compared well with those obtained by the laser flash method for similar coatings. The thermal conductivity of coatings shows an increasing tendency with an increase in the coating's thickness.