The Potential of High-Velocity Air-Fuel Spraying (HVAF) to Manufacture Bond Coats for Thermal Barrier Coating Systems

Abstract Driven by the search for an optimum combination of particle velocity and process temperature to achieve dense hard metal coatings at high deposition efficiencies powder feed rates, high-velocity air-fuel spraying (HVAF) was developed. In terms achievable velocities temperatures, this can be classified between oxy-fuel (HVOF) cold gas (CGS). The particular advantages HVAF regarding moderate as well productivity efficiency suggest that application should also investigated manufacture MCrAlY (M = Co and/or Ni) bond coats (BCs) in thermal barrier coating (TBC) systems. work, corresponding spray parameters were developed based on detailed analyses. Different diagnostics carried out characterize working jet particles flight. with respect their microstructure, surface roughness oxygen content. assessed its effectiveness. Process calculations flow acceleration heating applied explain governing mechanisms characteristics. results show is a promising alternative manufacturing process.