Deposition characteristics, sintering and CMAS corrosion resistance, and mechanical properties of thermal barrier coatings by atmospheric plasma spraying.

Atmospheric plasma spraying (APS) was used to fabricate 4.5 mol% Y 2 O 3 stabilized ZrO 2 (YSZ) and 4.0 mol% Yb 2 O 3 and 0.5 mol% Y 2 O 3 co-stabilized ZrO 2 (YbYSZ) series coatings with different spraying parameters. This study presents the effects of particle size of feed powder and substrate temperature on the microstructure and performance of thermal barrier coatings. Single-pass and multi-pass experiments were conducted to explore the relationship between the splat and the coatings. The experimental results indicate that adjusting particle size of feed powders and deposition temperature can alter the splat behaviour and microstructure, improve anti-corrosion and anti-sintering abilities, and enhance the hardness and elastic modulus. Changes in parameters can cause changes in the microstructure of as-sprayed coatings. Lower substrate temperatures can lead to vertical cracks, finer powders can introduce more microdefects, and conventional sized powders can form larger pores. A coating deposited using a conventional feed powder at a substrate temperature of 800 °C shows excellent sintering resistance. A coating deposited using a fine feed powder on 800 °C substrate exhibits the best calcium‑magnesium-alumina-silicate (CMAS) corrosion resistance. • Substrate temperature influences flattening behaviour of YSZ splats. • Splat diameter affects its morphology. • Top coat (TC) was deposited by regulating substrate temperature and feed powder. • TC deposited with higher substrate and fine feed powder enhances anti-CMAS corrosion. • TC deposited with higher substrate and conventional feed powder improves anti-sintering. [ABSTRACT FROM AUTHOR]