Continuous process for producing alumina-titanium carbide composites
US5391339A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 31, 1992 |
| Grant date | Feb 21, 1995 |
| Priority date | — |
| Expiry date | Dec 31, 2012 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC04B35/64
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A method of making a continuously sintered ceramic body. A ceramic green body is prepared from a powder mixture comprising alumina, TiC (or Ti(C,N)), in a weight ratio of alumina to TiC of about 40:60-95:5, a densification aid, and TiO.sub.2 in a weight ratio of TiO.sub.2 to alumina plus TiC of 0:100 to about 2:98. The green body is prefired, then continuously rapid sintered by heating in a belt furnace in Ar or N.sub.2 containing up to 8 w/o H.sub.2 to about 1800.degree.-1920.degree. C. for a time sufficient to achieve a density of at least about 4.12 g/cc. The rate of travel of the prefired body through the belt furnace provides a heating rate above about 800.degree. C. between about 225.degree. C./min. and the rate at which the body experiences thermal shock. Carbon monoxide is intoduced to the atmosphere during the sintering step only after the temperature exceeds about 1400.degree. C. The amount of CO introduced is selected to inhibit reaction between the alumina and TiC. The CO may be introduced by placing a mass of graphite in the furnace such that CO is released only above 1400.degree. C. The body may be prepared from a homogeneous slurry, and the green body may be presinte…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.