explosive spray

       explosive spray

Explosive spraying: Oxygen and acetylene gas are used to ignite and burn, causing the gas to expand and explode, releasing thermal energy and shock waves. Floor. Figure 5 is a schematic diagram of an explosive spray gun.

Figure 5 Schematic diagram of explosive spraying

The basic feature of explosive coating formation is still generally considered to be the result of high-velocity molten particles colliding with the matrix. The biggest feature of explosive spraying is that the particles have high flying speed and high kinetic energy, so the explosive spraying coating has: ① high bonding strength between the coating and the substrate, ② dense coating, low porosity, ③ coating surface roughness after processing is low , ④ The surface temperature of the workpiece is low. Explosive spraying can spray metal, cermet and ceramic materials, but due to the high price, high noise and oxidizing atmosphere of the equipment, it is not widely used at home and abroad. The most successful explosive spray application in the world was a patent obtained by the Linde branch of the United Carbide Company in 1955, and its equipment and process parameters are still kept secret. Around 1985, China successfully developed explosive spraying equipment by the Institute of Aeronautical Materials of the Ministry of Aerospace Industry of China. In terms of Co/WC coating performance, the spraying performance is close to the level of the United Carbide Corporation of the United States.

In explosive spraying, when the acetylene content is 45%, the oxygen-acetylene mixture can produce a free combustion temperature of 3140 °C, but it may exceed 4200 °C under explosive conditions, so most powders can be melted. The powder is transported much longer in the high-speed gun than in the plasma gun, which is the reason for its high particle velocity.