Influence of a Multi-Gas Mixture on the Performance of a HPPS Plazjet System for a Thermal Barrier Coating

The Plazjet system usually works with a binary gas mixture of nitrogen and hydrogen for the deposition of a thick TBC (NiCrAlY as a bond coat and Zirconia as a top coat). In order to improve the performances of our spraying device and ensure good quality coating, different experiments were conducted. The substitution of N₂ or the classical binary mixture N₂/H₂ respectively by a binary N₂/He, and a ternary gas composition N₂/H₂/He leads to an evolution of the deposition efficiency and quality coating. In order to optimise the various ratio in the gas mixture, the evolution of experimental parameters such as voltage were analysed.