Thermal spraying is classified as a special welding process. The key advantage of thermal spraying is the negligible amount of heat introduced into the substrate material during the spraying process. Therefore, spraying methods do not cause thermal deformation, as opposed to pad welding.
Characteristics
Refurbishment by spraying is used in the case of elements working under constant and variable load, and elements exposed to corrosive and erosive agents, or both. The coating is joined with the native material in an adhesive manner. Depending on the applied method and filler, adhesion of the coating to the substrate is between 30-120 MPa. Due to a lack of full metallurgical connection of the coating with the substrate material, coatings made by spraying methods cannot be subjected to point pressure. The spraying method and coating material are selected depending on the operating characteristics, size, required hardness etc.
