Coating material in a powder form is fed into an oxygen-fuel gas combustion flame, melted and projected by the gasstream onto a prepared substrate. The energy source for the meltdown and propulsion Thermal flame spraying of the powder is oxygen and acetylene (the same as in a standard type oxy-acetylene welding set up).
Flame spraying requires a fusing process after being sprayed. This is done by using a torch to bring the part up to approximately 1950 degrees Fahrenheit. After being fused, the coating has virtually no porosity and a bond strength comparable to welding.
The vast majority of parts we flame spray are cylindrical and, therefore, are spun in a lathe or custom fixture during these processes. The fusion temperature, preheat and cooling requirements vary depending on the base metal and coating involved. Some of the materials we routinely flame spray are nickel-chrome-boron, cobalt-nickel-chrome-boron, nickel-tungsten carbide-chrome boron, and various other pure and alloyed metals.
- Operations/Repair Industry Representative