Enhancing the CMAS resistance of YSZ thermal barrier coatings via hybrid suspension/solution precursor plasma spraying with gadolinium doping
Year: 2025
Type: article
Abstract: Liquid feedstock plasma spraying is a promising method for producing thermal barrier coatings (TBCs) with a microporous structure, offering low thermal conductivity and good compliance to thermal stresses. However, the high porosity reduces their resistance to CMAS (calcium–magnesium–alumino–silicate) infiltration. This study explored a hybrid suspension/solution precursor plasma spraying (SPS/SPPS) technique to improve CMAS resistance and thermal cycling performance. A 25 wt.% 8YSZ suspension in ethanol was doped by dissolving various concentrations (0.25 M, 0.50 M, and 0.75 M) of Gd(NO 3 ) 3 ·6H 2 O. Coatings were deposited on Hastelloy-X substrates with a NiCoCrAlY bond coat, both as single layers and as top layers over conventional porous or dense-vertically cracked (DVC) 8YSZ. Microstructural, phase, and micromechanical analyses, including pillar splitting tests, were performed. Gd-doping enhanced the CMAS resistance by forming a protective apatite phase, although its benefits plateaued beyond a certain concentration. This method offers a flexible, cost-effective route to advanced TBCs.
Source: Ceramics International
Authors: Margherita Cescon, Stefania Morelli, Edoardo Rossi, Daniele Duranti, Wenjuan Cheng, Marco Sebastiani, Paola Palmero, Elisa Fiume, Bartolomeo Coppola, Alessandro Lanzi, Luca Lusvarghi, Giovanni Bolelli
Language: English
Subfield: Aerospace Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $3,830
Award: G6609105087
OpenAlex ID: W7106819736