Structure of thermal spray coating

       The process of thermal spraying determines the structure of the sprayed layer, which is a layered structure formed by stacking countless molten particles sent to the surface of the substrate by high-speed airflow. Generally, the flame gas spray or electric spray process uses ordinary high-pressure air, so the surface of the molten particles will be oxidized by the oxidizing gas in the air, which will form oxidative inclusions in the coating. During the formation of the coating, due to The condensation of molten particles collides with deformation and rebounds, and voids will be formed in the coating, so the spray coating is caused by oxidizing



The amount of oxidative inclusions in the coating and the number of pores in the coating depends on the thermal spraying material and spraying conditions. The heat source temperature is as high as plasma, the spray speed is as fast as supersonic spraying, and the environment is as good as gas spraying, wococarbide.com spraying, The low melting point and good toughness of the material will reduce inclusions and pores, and greatly improve the structure and performance of the spray coating. Remelting treatment after spraying will also eliminate the inclusions and pores in the coating. At the same time, the layered structure of the coating will become a homogeneous structure, and the bonding equipment with the collective surface will also change. This is also the development of the spraying process. The reason, Taizhou thermal spraying



The bonding force between the spray coating and the substrate is closely related to the process used. Generally, the combination of the sprayed layer formed by flame gas spraying or electric spraying and the substrate is a physical and mechanical combination. Plasma spraying, supersonic spraying and spraying and then remelting the coating and the collective combination, in addition to the physical and mechanical combination, there will also be metallurgy Combination, that is, the alloy diffusion between the collective metal and the sprayed metal, which greatly improves the bonding force of the sprayed layer and the substrate.