The difference between thermal spraying and spray welding

       1. The bonding mechanism of the coating is different

The bonding mechanism of thermal spraying includes mechanical bonding, metallurgical chemical bonding and physical bonding. Among them, mechanical bonding is the main bonding method, and the bonding mechanism of spray welding is chemical metallurgical bonding to achieve permanent bonding between atoms.



2. The heating conditions of the workpiece are different

Thermal spraying has no remelting process. Generally, the surface temperature of the workpiece can be controlled below 250°C. During spray welding, it will not deform or change the structure of the workpiece to melt the coating. The remelting temperature can reach 900°C or more, which will not only cause deformation of the workpiece, but also And it will cause annealing or incomplete annealing of most of the workpieces



3. The bonding state with the substrate is different

The bonding strength between the thermal spray coating and the surface of the substrate is mainly mechanical occlusion. Although there is micrometallurgical bonding, the bonding strength of the coating is not high. Generally, 30-50MPa melts and forms a metallurgical bond with the substrate surface, and the bonding strength can reach 343~ 440mpa



4. Kinds of different spray materials

Spray welding requires the use of self-fluxing alloy powder, while thermal spraying does not require high self-fluxing alloy powder, nor is it necessarily self-fluxing alloy powder



5. Different covering layer structure

The spray welding layer is uniform and dense, generally considered to have no pores, and the thermal spray coating has pores



6. Different carrying capacity

The thermal spray coating can not bear impact load and high contact stress, so it is suitable for surface spraying of various surface contact parts. The spray welding layer can bear impact load and high contact stress, and can be used for line contact.