Patent ID: 7582846

Claim:
A method of applying a coating to a substrate, said method comprising the steps of: introducing a process gas into a thermal spray gun at a flow sufficient for ionization and acceleration for the application of coatings; ionizing the process gas using one or more electric arcs to heat the gas to temperatures in excess of 2,000 degrees C. with the one or more electric arcs occurring between one or more cathodes and one or more anodes, the one or more electric arcs being seated in an arc attachment step; accelerating the ionized plasma gas to supersonic velocities by a nozzle, having a convergent/divergent section with a throat therein between downstream of the arc attachment step; injecting material feed stock into the resulting high velocity hot gas/plasma stream downstream of the accelerating nozzle throat either internal to the bore of the nozzle or at the exit of the nozzle; and accelerating the material feed stock by the high velocity hot gas/plasma stream to achieve particle velocities from 600 to 2000 m/sec.