Ultrahard multilayer coating comprising nanocrystalline diamond and nanocrystalline cubic boron nitride
US8007910B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 19, 2007 |
| Grant date | Aug 30, 2011 |
| Priority date | — |
| Expiry date | Nov 14, 2028 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/30
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
A multilayer coating (MLC) is composed of two chemically different layered nanocrystalline materials, nanodiamond (nanoD) and nano-cubic boron nitride (nono-cBN). The structure of the MLC and fabrication sequence of layered structure are disclosed. The base layer is preferably nanoD and is the first deposited layer serving as an accommodation layer on a pretreated substrate. It can be designed with a larger thickness whereas subsequent alternate nano-cBN and nanoD layers are typically prepared with a thickness of 2 to 100 nm. The thickness of these layers can be engineered for a specific use. The deposition of the nanoD layer, by either cold or thermal plasma CVD, is preceded by diamond nucleation on a pretreated and/or precoated substrate, which has the capacity to accommodate the MLC and provides excellent adhesion. Nano-cBN layers are directly grown on nanodiamond crystallites using ion-assisted physical vapor deposition (PVD) and ion-assisted plasma enhanced chemical vapor deposition (PECVD), again followed by nanodiamond deposition using CVD methods in cycles until the intended number of layers of the MLC is obtained.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.