Characteristic of thermal spray processes is the heating up of the material to be coated in the form of wire or powder feedstock inside or outside a spraying gun. The feedstock reaches the molten state or at least a state of high plastic deformability prior to impact on prepared surfaces. Then, the molten materials are accelerated towards the substrate, impacted and solidified on the surface of the substrate.
The innovative coating processes work by particle impact on the components to be coated. We distributes and improves thermal spray technology by constant development.
For heat transfer to the spraying feedstock thermal plasma jets, arcs (also plasmas in the sense of physics) or flames are used. These are generated inside a spraying gun by injection of process gases and / or electrical currents. The heat transfer results in partial or full melting or at least in high deformability of the feedstock in solid state.
The simultaneous momentum transfer by the flames, thermal plasma jets or atomizing gas streams accelerates spray particles towards the component to be coated. The achievable particle impact velocity depends on the applied spraying process and coating material. By relative movement between spraying gun and component to be coated the coating is build up pass by pass.
The DIN EN 657 standard "Thermal Spraying" comprises characteristic expressions and definitions of the particular thermal spray processes.
One major advantage of thermal spraying concerns the possibility to prevent excessive heating of the substrate material during the coating process. In general the substrate microstructure can be fully maintained. This opens up a wide application field. Often there is no alternative to thermal spraying for coating production, if economical boundary conditions are taken into consideration.
