Method for making porous acicular mullite-containing composites
US8871676B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 18, 2009 |
| Grant date | Oct 28, 2014 |
| Priority date | — |
| Expiry date | Oct 19, 2030 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC04B2235/3481
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
Porous composites of mullite and cordierite are formed by firing an acicular mullite body in the presence of a magnesium source and a silicon source. In some variations of the process, the magnesium and silicon sources are present when the acicular mullite body is formed. In other variations, the magnesium source and the silicon source are applied to a previously-formed acicular mullite body. Surprisingly, the composites have coefficients of linear thermal expansion that are intermediate to those of mullite and cordierite alone, and have higher fracture strengths than cordierite at a similar porosity. Some of the cordierite forms at grain boundaries and/or points of intersection between mullite needles, rather than merely coating the needles. The presence of magnesium and silicon sources during acicular mullite formation does not significantly affect the ability to produce a highly porous network of mullite needles.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.