The term "thermal spraying" covers a range of spray processes. They are classified according to the type of spray material, type of operation or type of energy source, as defined in the standard EN ISO 14917.
By virtue of their process-related properties, the individual thermal spray processes do not compete for applications, but instead complement each other. In order to produce spray coatings, all thermal spray processes require two types of energy: Thermal energy and kinetic energy.
The energy sources currently in use are the oxy-fuel-gas flame, the electric arc and the plasma jet. Thermal energy is needed to melt or fuse the spray material. Kinetic energy, coupled to the particle velocity, influences the coating density, the bond strength of the coating itself and the bond strength of the coating to the base material. The kinetic energy in the different thermal spray processes varies greatly and also depends on the coating material and particle size.