Process for treating a piece of tantalum or of a tantalum alloy
US10287667B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 22, 2016 |
| Grant date | May 14, 2019 |
| Priority date | — |
| Expiry date | Nov 23, 2037 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC22F1/18
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A process for treating a piece of tantalum or of a tantalum alloy, which consists in: placing the piece in a furnace and heating the furnace under vacuum at least at 1 400° C.; forming a carbon multilayer in the peripheral part of the piece, by injecting, in the heated furnace, a gas carbon source at a pressure ≤10 mbar, the multilayer comprising at least one layer C1 of tantalum carbide, which is located at the surface of the piece, and two layers C2 and C3 comprising a carbon content lower than the carbon content of the layer C1; stopping the formation of the multilayer by cooling the piece; placing around the piece a device capable of trapping carbon, oxygen and nitrogen to protect the piece from carbon and oxygen and nitrogen traces present in the furnace; causing the diffusion of carbon present in the layer C1 towards the layers C2 and C3, by heating the furnace under vacuum, the piece being held in the protecting device; and stopping the diffusion of carbon in the piece by cooling the piece under vacuum before the carbon present in the multilayer reaches the center part of the piece. Thus, a piece the surface of which is free from TaC, the center part of which is free from ca…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.