Oxygen and fuel (acetylene most common) is fed into the barrel along with a charge of powder. A spark is used to ignite the gas mixture and the resulting detonation heats and accelerates the powder to supersonic velocity down the barrel. A pulse of nitrogen is used to purge the barrel after each detonation. This process is repeated many times a second. The high kinetic energy of the hot powder particles on impact with the substrate results in build up of a very dense and strong coating.
|Heat Source||Charge Detonation|
|Flame Temperature (°C)||1,500 to 4,000|
|Particle Velocity (m/sec)||600 to 1,200|
|Porosity (%)||< 1|
|Coating Adhesion (MPa)||> 70|