Thermal spray equipment and technology

       Although the equipment differs according to the method of thermal spraying, according to the principle of thermal spraying technology, the equipment is mainly composed of spray gun, heat source, coating material supply device, control system and cooling system.



The thermal spraying process is as follows: workpiece surface pretreatment→workpiece preheating→spraying→coating post-treatment



1) Surface pretreatment



In order to combine the coating with the substrate material well, the surface of the substrate must be clean and rough. There are many methods for cleaning and roughening the surface. The choice of the method should be based on the design requirements of the coating and the material, shape, thickness, surface It depends on the original condition and construction conditions. The purpose of purification treatment is to remove all dirt on the surface of the workpiece, such as oxide scale, oil stains, paint and other dirt, the key is to remove the surface of the workpiece and the grease that penetrated into it.



2) Preheating



The purpose of preheating is to eliminate the moisture and moisture on the surface of the workpiece, increase the interface temperature when the sprayed particles are in contact with the workpiece, so as to improve the bonding strength between the coating and the substrate, and reduce the stress caused by the difference in thermal expansion between the substrate and the coating material. resulting in cracking of the coating.



3) Spraying



Which spraying method is used for spraying mainly depends on the selected spraying material, the working conditions of the workpiece and the requirements for the coating quality.



4) Post-coating treatment



Sometimes the coating obtained by spraying cannot be used directly, and a series of post-treatments must be carried out.