Plasma spraying of mullite and pore formers for thermal insulating applications

Porous materials are widely used in various fields requiring thermal insulation properties, such as the aircraft industry, with barrier coatings. In applications, plasma-sprayed yttria-stabilized zirconia proved to be a highly effective insulating coating. With higher void content, aluminum silicate space industry (Intermediate eXperimental Vehicle, for instance) due their low density and conductivity. this study, several sprayed coatings were evaluated candidates conductivity applications. deposits produced thanks pore former introduction into plasma plume, so integrated inside Two formers used, aromatic polyester mineral agent, leading different microstructures. mullite microstructures, 80% porosity removal by treatment, carried out, while layered microstructures obtained agent enthalpy plasma. Furthermore, thick spraying configurations. A static spray set-up allowed porous one centimeter coating production without any manufacturing defects before after treatment. This was made possible throughout deposit temperature control, via cryogenic carbon dioxide cooling system.