Introduction of Ceramic Rod Spraying Process

The ceramic rod is a welding rod-shaped flame spraying material specially manufactured for the ceramic rod flame spray gun. The rods for thermal spraying are generally ceramic rods, and they are made into a welding rod-shaped flame spraying material because they cannot be drawn into wire materials for the poor toughness. The ceramic surface spraying is applied on the surface of the substrate to form a ceramic coating, which acts as a wear-resistant and anti-corrosive effect. The oxygen is mixed and burnt with acetylene to melt the ceramic rod, and the molten ceramic rod material is atomized into fine droplets by compressed air and sprayed onto the substrate, forming a ceramic coating. Therefore, the coating is dense with low porosity, and the bonding strength is good, and there is no edge effect of the flame flow during powder flame spraying and plasma spraying. So what is the spraying process of ceramic rods?

1. Pretreatment of the substrate surface. In order to have good bonding strength between coatings and the substrate, the surface of the sprayed substrate must be pretreated by methods such as purification, solvent cleaning, lye cleaning, ultrasonic cleaning and heat treatment.

2. The roughening treatment. Make the surface of the purified substrate subjected to sandblasting or the like to form a rough uneven surface for good bonding force with the coating layer. The main methods of surface roughening treatment include: sandblasting roughening, spraying self-bonding metal layer, and mechanical processing methods such as vehicle groove, embossing knurling and planar groove, etc.

3. Spraying process. Perform ceramic spraying on the roughened substrate, the thickness of the ceramic coating can be controlled according to actual requirements. The optimum spray ceramic coating thickness is 0.3mm~1.0mm. For work pieces with complex shapes, they can be clamped to a fixture such as a lathe for ceramic spraying.

4. Post-processing. If the surface of the workpiece requires a fine fit, it needs to be ground after spraying. If it is a corrosion-resistant part like an acid-resistant pump casing, it also needs to be “sealed”. Since the sprayed ceramic layer has a certain gap, the porosity is about 4 to 12%, and the pores communicate with each other and extend from the surface to the substrate. In order to prevent the corrosive medium from penetrating the substrate through the pores, it is necessary to close the micropores.