In wire flame spraying, the process material, in wire form, is continuously fed into the acetylene-oxygen-flame by a suitable wire feed unit. The speed at which the wire is fed in is in accordance with the rate of deposition of the spraying materials in the respective thermal energy source. The heated material in the melting area at the tip of the wire is expelled as droplets, accelerated and sprayed onto the surface of the component by a compressed gas. In this way the amount of kinetic energy, and also the particle velocity, caused by the pressure of the propellant gas, or the propellant gas velocity, can be pre-set.
Wire flame spraying is a common process. The process temperatures are maximum 3,160 °C and the attainable particle velocity is approximately 200 m/s/.
Particularly remarkable are applications with pure molybdenum, which yield with a very low friction coefficient and resistance to cold welding (galling). Typical examples of this can be seen in the automobile industry in piston rings, gearshift forks, synchroniser rings, and clutch rings, among others.