Plasma transferred arc surfacing (PTA-surfacing)
Being a modern advanced technology, the plasma transferred arc (PTA) surfacing is used wide to coat function areas of high responsibility details with special materials, which are resistant against intensive wear, corrosion, thermal and percussive loading.
- Electrode
- Plasma nozzle
- Focusing nozzle
- Shielding nozzle
- Work piece
- Ballast resistance
- Power source
- Oscilation unit
The pilot arc is ignited generator between non-consumable tungsten electrode and so called, plasma forming nozzle with the help of high voltage. The pilot arc, in its turn, creates the transferred arc between tungsten electrode the treated detail. The transferred arc is constricted by the plasma forming nozzle, getting higher temperature and concentration. The additive powder is fed into the arc column.
It is possible to regulate process conditions so, that the whole amount of powder and only a thin film on the detail surface are melted. As a result, a metallurgical bond between cladded layer and detail is provided with the minimum dilution of the detail material (3-10%). Ar is basically used for arc plasma supply, powder transport and molten material shielding.
Comparing with conventional arc surfacing technologies the PTA offers:- high deposition rate up to 10 kg/h
- high quality of deposited metal
- minimum penetration into base metal (< 5%)
- minimum losses of filler material
- deposits between 0,5 - 5,0 thickness and 3,0 - 50,0 mm width can be produced rapidly in a single pass
- Fe-, Ni-, Co-, Cu- base alloys as well as composite materials can be clad
In a competition with the laser surfacing the PTA technology offers much more high productivity, comparable high quality of deposits and significantly lower costs.
Typical application areas of the PTA technology
