Disadvantages of traditional hot spraying and cold spraying

Thermal spraying includes flame spraying, arc spraying, plasma spraying, explosive spraying and supersonic flame spraying. They are characterized in that arc, flame, plasma or laser are used as heat sources to heat the powder to a molten or semi-molten state, and then the droplets are bonded to the surface of the workpiece to form a coating. Therefore, in the process of thermal spraying, there will be problems such as powder oxidation, phase transformation, decarbonization or changing the physical and chemical properties of the original powder, and it will also have adverse thermal effects on the matrix. Lianyi electromechanical, and cold spraying process has many advantages, because the temperature of powder particle deposition is low. Compared with thermal spraying, the biggest advantage is that the working temperature of spraying is much lower than all thermal spraying processes.

Because cold spraying is to deposit high-speed powder particles on the substrate, it has many advantages and its own disadvantages:

1. Brittle materials, including brittle ceramic materials and brittle metal materials, are difficult to deposit coatings, and these materials cannot be formed by cold spraying.

2. When spraying some powder particles, expensive He must be used as carrier gas to obtain high quality coating.

3. Cold spraying can't diffract and spray the surface of complex parts.