Preparation of solid aggregates of high density boron nitride crystals
US5549731A · kind A · utility
Inventors
Key dates
| Filing date | Dec 21, 1994 |
| Grant date | Aug 27, 1996 |
| Priority date | — |
| Expiry date | Dec 21, 2014 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB01J2203/0685
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
Method and apparatus for compaction of powder of high density boron nitride, having an initial particle diameter of at least two microns, into a high density crystal aggregate of between 1 mm up to about 1 cm in diameter, the resulting crystal aggregate having a zincblende form, the wurtzite form or mixtures of the zincblende and wurtzite forms. High density aggregates of boron nitride, preferably having particle sizes with diameters at least 2 .mu.m, are placed in a hollow, substantially cylindrical first container of metal, and the first container is surrounded by a fluid-like material of metal or metal powder having a shock wave velocity V. The first container and fluid-like material are placed in a substantially cylindrical second container that is purged of substantially all air and sealed. The second container has a rigid side wall and two rigid end walls. A high explosive, having a detonation velocity D of at least 6 km/sec and preferably at least 8 km/sec, is positioned at one end wall and along at least a portion of the side wall of the second container. The high explosive is detonated, and an approximately radially directed pressure wave moves through the fluid-like mater…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.