A Methodology to Control the Microstructure of Plasma Sprayed Coatings

摘要: The aim of this thesis is to enhance the overall understanding plasma spray process and increase control reproducibility coating properties. This was performed by establishment relationships between controllable parameters, in-flight properties injected particles (velocity temperature), microstructure were used establish a strategy. research in two areas. first area numerical simulation using computational fluid dynamics model plasma, particle properties, interactions. second applied experimental research, focused on observations, measurements statistical modeling techniques. work included evaluation microstructures, scanning electron microscopy an in-house image analysis code. It shown that satisfactorily modeled linear regression. Particle velocity temperature could be independently controlled arc current primary gas flow rate. variables having largest influence found velocity, temperature, substrate angle. strategy developed creation maps, describing individual features, deposition efficiency, as functions temperature. Based these maps methodology, called windows, established. In method each desired criteria are specified corresponding ranges determined. Keeping within ensures meet its requirements. also prior implementation window enhanced can achieved reduction gun tolerance limits. should regarded foundation for tool which optimized on-line industrial production.