The use and difference of thermal spray technology and spray welding technology.

       

There is no fundamental difference between spraying and spray welding. The key is that spraying is mainly used for surface anticorrosion and hardness improvement of workpieces. Spray welding is mainly used for welding. Due to different uses, the solders used are different. Devices can be generic.

1) There is no remelting process for spraying under different heating conditions of the workpiece, and the surface temperature of the workpiece can always be controlled below 250 °C, which generally does not cause deformation and change the original structure of the workpiece. This is beneficial for spray repairing workpieces with complex shapes, thin walls, long sleeves and some important parts. The powder layer must be melted by spray melting, and the temperature of the remelted and sintered workpiece can reach above 900 °C, which is easy to cause stress and deformation, and most workpieces will undergo annealing and incomplete annealing.

 

    2) The bonding with the surface of the substrate is different. The bonding between the spraying and the surface of the substrate is mainly mechanical occlusion, and there are also tiny microscopic welding, and the bonding strength is not high; generally 20MPa~65MPa. Spray welding is to form a metallurgical bond with the surface of the substrate through the melting of the powder layer, and the bond strength can generally reach 343MPa~441MPa.

 

    3) Different powders used The powder used for spray melting must be self-fluxing alloy powder, and the powder used for spraying is not limited.

 

    4) The sprayed layer structure is different, the sprayed melted layer is uniform and dense, and it is generally considered that there is no porosity while the sprayed layer has certain pores.

 

    5) With different load bearing performance, the spray coating can not bear impact load and high contact stress, and is suitable for various surface contact coordination. The melt-blown layer has high bonding strength, can withstand impact loads, can be used in line contact and other occasions, and can withstand high contact stress.