Sealing of ceramic and cermet parts, sealing material therefor and ceramic seal obtained
US4316936A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 4, 1979 |
| Grant date | Feb 23, 1982 |
| Priority date | — |
| Expiry date | Sep 4, 1999 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/2993
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
The invention provides a particulate sealing material for use in preparing hermetic seals between ceramic and cermet members, which material comprises at least 70 wt. % refractory oxide and minor quantities of non-vitreous additive comprising SiO.sub.2, MgO and B.sub.2 O.sub.3. This particulate sealing material is conveniently pressed into the form of a coherent element shaped to suit the particular sealing operation concerned, e.g. the sealing of an open end of a ceramic arc tube to a cermet closure therefor. The invention also provides a method of sealing a ceramic component to a cermet member by interposing said sealing material between the opposed faces of the component and member and applying heat and pressure to sinter the sealing material and achieve a seal between the component and member. It has been observed that the sintered sealing composition in the completed seal can have a microstructure characterized by flattened refractory oxide-rich islands aligned generally parallel to said faces and substantially surrounded and interconnected by non-vitreous material rich in oxides of silicon, magnesium, and boron and said non-vitreous material forming layers thinner than said i…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.