Common thermal spray technologies and advantages

       The so-called thermal spraying is to use various heat sources such as gas, liquid fuel and electric arc, plasma arc to heat and melt or soften the sprayed material, and rely on the power of the heat source itself or an external compressed air flow to atomize or push the molten particles into sprayed particles. A process method in which the beam is sprayed onto the surface of the substrate at a certain speed to form a coating. So, what are the common thermal spraying technologies?



1. Flame spraying: flame spraying includes wire flame spraying and powder flame spraying. The wire flame is to send the metal wire into the spray gun at a certain speed, so that the end is melted in the high temperature flame, and then atomized and blown away with compressed air, and deposited on the surface of the pretreated workpiece; powder flame spraying method : The difference between it and wire flame spraying is that the spraying material is not wire but powder.



2. Arc spraying: Arc spraying generates an arc between two wire-shaped metal materials, and the metal welding wire is gradually melted by the heat generated by the arc, and the melted part is sprayed by the compressed air flow to the surface of the substrate to form a coating.

3. Plasma spraying: Plasma spraying is also a kind of arc spraying, including atmospheric plasma spraying, protective atmosphere plasma spraying, vacuum plasma spraying and water stable plasma spraying. Plasma spraying is carried out by using plasma arc. The ion arc is a compression arc. Compared with the free arc, its arc column is thin, the current density is large, and the gas ionization degree is high. Therefore, it has the characteristics of high temperature, concentrated energy and good arc stability.

From the analysis of the principle and process of thermal spraying, thermal spraying technology is widely used, and its main advantages are as follows:



1. The equipment is portable and can be constructed on site.



2. The process is flexible and the operation procedures are few. Can be repaired quickly and reduce processing time.



3. Strong adaptability, generally not limited by the size of the workpiece and the site.



4. The coating thickness can be controlled.



5. In addition to spray welding, the heating temperature of the base material is low, the deformation of the workpiece is small, and the crystal phase structure and performance change are also small.



6. It is suitable for parts of various base materials, and various protective coatings and functional coatings can be prepared on the surface of almost all solid materials.