Method for minimizing decarburization and other high temperature oxygen reactions in a plasma sprayed material
US5217746A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 13, 1990 |
| Grant date | Jun 8, 1993 |
| Priority date | — |
| Expiry date | Dec 13, 2010 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC23C4/134
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
A method is disclosed for spray coating material which employs a plasma gun that has a cathode, an anode, an arc gas inlet, a first powder injection port, and a second powder injection port. A suitable arc gas is introduced through the arc gas inlet, and ionization of the arc gas between the cathode and the anode forms a plasma. The plasma is directed to emenate from an open-ended chamber defined by the boundary of the anode. A coating is deposited upon a base metal part by suspending a binder powder within a carrier gas that is fed into the plasma through the first powder injection port; a material subject to degradation by high temperature oxygen reactions is suspended within a carrier gas that is fed into the plasma through the second injection port. The material fed through the second injection port experiences a cooler portion of the plasma and has a shorter dwell time within the plasma to minimize high temperature oxygen reactions. The material of the first port and the material of the second port intermingle within the plasma to form a uniform coating having constituent percentages related to the powder-feed rates of the materials through the respective ports.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.