Alloy, typically NiCrBSi, in which boron and silicon lower the melting point and act as fluxes, cleaning oxides off the particles and substrate when the coating is remelted. After fusing at around 1,000 to 1,150 °C the coating is dense, metallurgically bonded and can reach about 60 HRC, more with tungsten carbide blended in. It is the standard material for spray-and-fuse.
Rebuild the pump plunger with self-fluxing alloy, 60 hardness after fuse, grind to size.
Also heard as
- self-fluxing powder
- NiCrBSi
Related terms
Spray and fuse
Spraying a self-fluxing alloy, then remelting it with a torch, induction or furnace so it fuses to the part.
Flame spray
The simplest thermal spray process: powder or wire melted in an oxy-fuel flame and blown onto the part.
WC-Co
Tungsten carbide in a cobalt binder, the most common wear-resistant thermal spray coating.