Layer with controlled grain size and morphology for enhanced wear resistance
US7192660B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Apr 26, 2004 |
| Grant date | Mar 20, 2007 |
| Priority date | — |
| Expiry date | Feb 5, 2025 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/30
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
Wear resistance of the prior-art Ti(C,N) layers can be considerably enhanced by optimizing the grain size and microstructure. Considerably better wear resistance in, for example in many carbon steels, can be obtained by modifying the grain size and morphology of prior art MTCVD Ti(C,N) coatings. The improved coating is composed of small columnar crystals. Doping by using CO, CO2, ZrCl4, HfCl4 and AlCl3 or combinations of these can ensure the control of the grain size and shape. Doping has to be controlled carefully in order maintain the columnar structure and also in order to avoid nanograined structures and oxidization. The preferred grain size should be in the sub-micron region with the grain width of from about 30 to about 300 nm. The length to width ratio should be more than 5, preferably more than 10 and the coating should exhibit a strong preferred growth orientation along 422 or 331. The XRD line broadening should be weak.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.