The combination of spray coating and spray welding layer with base metal is different. The exothermic chemical reaction occurs when the nickel-clad aluminium is heated by spray flame beam, and the micro-metallurgical bonding bottom layer and working layer are formed on the surface of carbon steel with RZ > 50 micron. The bonding between spray welding layer and base metal is pure metallurgy. Gold bonded coating.
            The densification of the coating is different, the spray welding layer is dense, and there are a few voids in the spray coating. The spraying coating can generally withstand large area contact, and it is mostly used on working surfaces with lubrication conditions, matching surfaces and other working conditions with less stress. However, the spraying coating can withstand large impact force, extrusion stress or contact stress.
            Different spraying materials require the use of self-fluxing alloy powder, while spraying does not require the self-fluxing of powder, and is not necessarily self-fluxing alloy powder. All kinds of self-fluxing alloy powder can be used for both spraying and spraying, but spraying powder without self-fluxing can only be used for spraying but not for spraying process. In the process of spraying and welding, the preheating temperature before spraying is different, the workpiece is affected by heat differently, and the structure and performance of the workpiece after spraying are also different.