The Flame (or Combustion) Powder Spray process uses a similar technique as the Flame Wire Spray process, except that the wire feedstock is replaced with a powder.
The main advantage of this process is that a much wider range of materials (such as nickel or cobalt based self fuxing alloys or ceramic materials) can be easily processed into powder form giving a larger choice of coatings. Many alloys are difficult or cannot be produced in a wire form and for this reason it was developed.
The process relies on the chemical reaction between oxygen and a fuel of combustion to produce a heat source. This heat source creates a gas stream with a temperature in excess of 3,000°C with correctly balanced conditions between oxygen and acetylene. The feed stock material to be sprayed is fed into the flame in the form of a powder to melt and the thermal expansion of the combustion is then used to atomize and accelerate the particles onto the substrate.