Method of surface treatment of titanium metal
US7291229B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Sep 11, 2003 |
| Grant date | Nov 6, 2007 |
| Priority date | — |
| Expiry date | Jun 22, 2024 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC23C8/36
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
A method of carburizing treatment is proposed in which if carburizing is carried out at a low temperature, carbon will not turn amorphose and deposit on the surface of a titanium metal but reliably penetrate into between metallic atoms. It is a method of surface treatment of a titanium metal comprising the steps of heating the titanium metal to a temperature of 400-690° C. in a cleaning gas atmosphere containing hydrogen gas, subjecting the surface of the titanium metal to cleaning by applying a DC voltage of 200-1500 V, and plasma carburizing in an atmosphere comprising a carburizing gas having an atomic weight ratio of hydrogen atoms (H) to carbon atoms (C) adjusted to 1≦H/C≦9 at a pressure of 13-400 Pa and a temperature of 400-690° C. Ionization reaction in the gas is suppressed suitably. Because there exists no excessive carbon which is not used for carburization but turns soot or glass-like carbon, in the atmosphere during carburization, carburizing reaction progresses smoothly.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.