Formation of vertical cracks in air plasma sprayed YSZ coatings using unpyrolyzed powder |
| |
Affiliation: | 1. CEA-DAM, Le Ripault, BP 16, 37260 Monts, France;2. Safran, Pôle Matériaux et Procédés, Rue de Jeunes Bois, Châteaufort, CS 80112, 78772, Magny-Les-Hameaux, France;3. Safran-Snecma, Rue Maryse Bastié, BP 129, 86101 Châtellerault, France;4. LEMTA Université de Lorraine, 2 Avenue de la forêt de Haye, BP 160, 54504, Vandoeuvre-Lès-Nancy, France |
| |
Abstract: | Thick thermal barrier coatings (TTBCs) with vertical cracks deposited by air plasma spray (APS) and solution precursor plasma spray (SPPS) techniques have been widely investigated to achieve good thermal insulation along with reasonable service life. In this study, synthesized unpyrolyzed YSZ powder was air plasma sprayed in order to produce segmentation crack TTBCs. The microstructure and hardness of the deposits were then compared with those of the conventional TTBCs and dense vertically cracked (DVC)TTBCs. In this regard, spraying parameters were optimized to achieve deposits with the appropriate amount of unpyrolyzed particles in them to assist inducing vertical cracks in the deposited layers. The effect of the unpyrolyzed particles on microstructure, porosity, and microhardness of plasma sprayed coatings were also evaluated and compared. The new fabricated coating showed a bimodal structure combining non-molten sub-micron size particles and conventional splats along with segmentation cracks with higher amount of porosity and lower hardness compared to those of the DVC coatings. The results implied that, depositing unpyrolyzed powder by APS, as a new approach for achieving segmentation crack TTBCs, is very promising. |
| |
Keywords: | Thick thermal barrier coatings Air plasma spray Unpyrolyzed YSZ powder Segmentation cracks |
本文献已被 ScienceDirect 等数据库收录! |
|