In flame spraying with powder the particles are softened or melted in an oxyacetylene flame and transferred to a prepared workpiece by the expanding gases. An additional gas stream can be used to assist with powder particle transfer.The second stage of the process, fusing the sprayed coating to the workpiece, is usually done with an oxyacetylene burner.
Alternatively, for series production, fusing can be carried out by induction heating or in a vacuum furnace.The bonding of the sprayed coating to the workpiece is significantly increased by the fusing process, which creates metallurgical bonds between the powder particles and also between the coating and the work-piece. The coating becomes liquid-tight and gas-tight.
Advantages:
- Metallurgical bonding
- Can use induction or vacuum furnaces
- Liquid-tight and gas-tight
A specially designed Oxy-acetylene torch is used for powder welding. The work piece is heated with the torch. The powder is introduced into the gas stream from the integral powder hopper and then transferred to the work piece through a flame.
This process is similar to the Oxy-acetylene process with the exception that the hardfacing takes place at lower temperatures. This minimizes oxidation and distortion of the work piece ad enables easy surfacing of edges.
Advantages:
- Low Dilution
- Easy Application
- Low Distortion
- Ideal for Edge Building
