PLASMA POWDER SURFACING (PTA - Plasma Transferred Arc):
This is the state-of-art-technology of surfacing which subject matter is the electric arc generated between tungsten electrode and surfacing material. During this generation is from incoming inert gas - argon - created a high concentrated plasma flow of high temperature. The powder material is added in this flow and creates the surface.
| Advantages | Disadvantages |
|---|---|
| Thanks to plasma concentration is the area of melting relatively narrow and this minimizes the basic material thermal affection | Added powder material is the most expensive added material in comparison with electrode or wire |
| Very thin transition filter is created during surfacing between basic material and the welding surface itself with the thickness of ca.1-2mm | |
| Together with the positioner a very uniform layer of surface can be created (welding surface high tolerance 1mm) which minimizes costs of subsequent machining |
- Added material - powder
- Plasma gas - argon
- Gaseous shield - nitrogen
- Tungsten electrode
- Surface
- Background
For Plasma powder surfacing we use the Eutronick 200/400 equipment from the company Castolin (www.eutectic.com). Positioner with automatic feed allows very accurately surface cylindrical and spherical surfaces.
As added material we use mainly cobalt base powders so cold stellits(www.stellite.com), which create highly hard layers (up to 55HRC) resistant to abrasion, chemical and heat corrosion and contact load.