Phase composition and thermal conductivity of zirconia-based thermal barrier coatings

Abstract

Atmospheric plasma spraying of powder materials has been used to produce thermal barrier coatings (TBCs) based on ZrO₂ stabilized with 7 wt % Y₂O₃, including coatings doped with neodymium and samarium oxides, for state-of-the-art and next-generation high-temperature gas turbine engines. Doping with neodymium and samarium oxides has been shown to reduce the thermal conductivity of the TBCs by 10–20%. At the same time, changes in the phase composition, crystal structure parameters, and microstructure of the TBCs during heat treatment at the service temperature lead to an increase in the thermal conductivity of all the coatings by 50–70%.