Enhanced alumina layer with texture
US7442431B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Nov 2, 2005 |
| Grant date | Oct 28, 2008 |
| Priority date | — |
| Expiry date | Nov 1, 2026 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/265
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
A refined method to produce textured α-Al2O3 layers in a temperature range of 750-1000° C. with a controlled texture and substantially enhanced wear resistance and toughness than the prior art is disclosed. The α-Al2O3 layer is formed on a bonding layer of (Ti,Al)(C,O,N) with increasing aluminium content towards the outer surface. Nucleation of α-Al2O3 is obtained through a nucleation step composed of short pulses and purges of Ti-containing and oxidizing steps. The α-Al2O3 layer has a thickness ranging from 1 to 20 μm and is composed of columnar grains. The length/width ratio of the alumina grains is from 2 to 15, preferably 6 to 10. The layer is characterized by a strong (110) growth texture, measured using XRD, and by the low intensity of (012), (104), (113), (024) and (116) diffraction peaks.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.