Thermal spray, also known as spray welding or hot spraying, is to molten or semi-molten the coating material, thus enabling the high-speed air flow to collide and adhere to the surface of work pieces and solidify rapidly, accumulate to form the coating layers.

The coating materials can be powder , wire or stick bar. Since the variety of coating materials can perform the functions of corrosion resistant, abrasion resistant heat resistant and insulation, thermal spray technology has been widely used in aerospace, automotive, energy, iron and steel, metalwork, petrochemical engineering, optical FPD, semiconductor, paper industry, machinery maintenance, etc. Thermal spray is a key technology in surfacing treatment , and thermal spray materials include metals , alloys , carbides, ceramics and even polymers.