Plasma transferred wire arc thermal spray apparatus and method
US5808270A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 14, 1997 |
| Grant date | Sep 15, 1998 |
| Priority date | — |
| Expiry date | Feb 14, 2017 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB05B13/0636
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A plasma transferred wire arc thermal spray apparatus and method producing an extended-arc and supersonic plasma jet stream for applying a dense metallic coating on a substrate, such as a concave internal surface of a bore. The apparatus includes a plasma generating torch assembling having a cathode and an anode nozzle surrounding the cathode and a wire feeder which continuously feeds the tip of a wire feedstock opposite a constricted nozzle orifice and wherein the wire feedstock is maintained at the same positive electrical potential as the nozzle. Plasma gas is directed into the nozzle, preferably generating a vortex flow around the cathode and exiting the restricted nozzle orifice. The improved apparatus includes a pilot power supply and a high voltage or high frequency power supply which initiates the electric arc and the constricted plasma arc and a separate main power supply which extends the constricted plasma arc to the wire tip. In the disclosed bore coating apparatus and method, the plasma torch assembly is rotated about the longitudinal axis of the wire feedstock while maintaining the electrical connection between the wire feedstock and the nozzle. The apparatus further …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.