Why sand blasting before metal thermal spraying?

Before the mechanical workpiece is thermal sprayed, most of them need to be sandblasted, such as: dryer spraying, mechanical function roller spraying processing, shaft workpiece spraying, etc., before the thermal spraying repair, the surface needs to be sandblasted first, the main purpose is to improve the cleanliness and roughness of the workpiece surface.

Sandblasting is also a surface treatment process, he is the use of compressed air as a power, so that the spray high-speed sandblasting to the surface of the workpiece, so that the surface of the workpiece changes, the spray material selected by the sandblasting is generally quartz sand, emery, etc., the material used in the repair of different workpieces is different. In the process of sandblasting, the abrasive has an impact on the workpiece, prompting the workpiece surface to obtain a certain degree of cleanliness and roughness, thereby changing the mechanical properties of the workpiece surface, so that in the later thermal spraying processing, the adhesion between the workpiece and the coating can be increased, the bonding strength can be enhanced, and the service life of the coating can be improved.

Sandblasting is a more thorough, universal, rapid and efficient cleaning method, which can be selected between different roughness, which is impossible to achieve by other processes; Compared with manual grinding, its efficiency and surface cleaning strength are also greatly improved.

Sandblasting can not only be used in thermal spray processing, but also in other applications. Such as: workpiece coating, bonding before the surface cleaning; Clean and polish the rough surface of the forged workpiece after heat treatment; Machining burr cleaning, etc.