Patent · US Expired

Silicon nitride ceramic and a process for its preparation

US5059565A · kind A · utility

4Cited by

7References

9Claims

0Family size

Assignee

Hoechst GmbH · DE

Inventors

Marcellus Peuckert · Hofheim, DE
Cornelia Boberski · Hofheim, DE

Key dates

Filing date	Feb 16, 1990
Grant date	Oct 22, 1991
Priority date	—
Expiry date	Feb 16, 2010

Classification

Technology area (CPC C)Chemistry; Metallurgy
CPC primaryC04B35/584
WIPO fieldMaterials, metallurgy
WIPO sectorChemistry

Abstract

A multi-phase ceramic which is resistant to high temperatures and contains 25-85 % by weight of crystalline .beta.-silicon nitride, 11 to 70% by weight of crystalline cubic HfO.sub.2 and an amorphous glass phase which, in addition to silicon, contains at least one of the elements magnesium, yttrium and/or the rare earths and if appropriate aluminum, has good mechanical properties. To prepare the ceramic, a mixture of 25-85% by weight of pulverulent a-silicon nitride, 11 to 70% by weight of monoclinic HfO.sub.2 and 5-20% by weight of at last one oxide of the elements magnesium, yttrium and/or the rare earths (from Sm to Yb) is shaped to a body and this is sintered to give a dense body at 1,700-2,000.degree. C.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.