Method and apparatus for thermochemical treatment
US4900371A · kind A · utility
10Cited by
4References
8Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Oct 16, 1987 |
| Grant date | Feb 13, 1990 |
| Priority date | — |
| Expiry date | Oct 16, 2007 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC23C8/36
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
Known techniques of plasma case hardening of workpieces may fail to provide sufficient treatment to re-entrant portions, such as fine holes, in the workpiece. This specification discloses a technique of pulsed plasma treatment in which the duration of the plasma pulses and the intervals between them are selected to allow a substantially even distribution of the gas which forms the plasma over all the surface to be treated of the workpiece.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.