Fixture for brittle pre-crack introduction in ceramic specimen
US4901582A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 29, 1987 |
| Grant date | Feb 20, 1990 |
| Priority date | — |
| Expiry date | Dec 29, 2007 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2203/0405
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A fixture capable of a brittle pre-crack introduction of prescribed shape and size in a ceramic specimen with high reproducibility comprises an anvil provided on the upper side thereof with a central groove perpendicularly intersecting a specimen to be mounted thereon for pre-crack introduction and a groove for positioning the specimen and a platelike pusher possessing a smooth and flat lower surface. To ensure stability of the brittle pre-crack introduction, the positioning groove in the anvil is so formed as to rise rectangularly in an equal length on either side of the central groove and the overall length of the positioning groove, i.e. the sum of the lengths of the raised portions plus the width of the central groove, is kept from exceeding the length of the specimen. To enhance the results of the introduction, the lower surface of the pusher is finished with roughness of not more than 0.8S and flatness of not more than 0.01 mm.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.