Process for making cubic boron nitride from coated hexagonal boron nitride, and abrasive particles and articles made therefrom
US5015265A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 14, 1989 |
| Grant date | May 14, 1991 |
| Priority date | — |
| Expiry date | Jun 14, 2009 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC04B35/5831
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
Abrasive particles and articles made from cubic boron nitride derived from coated hexagonal boron nitride which is substantially free of oxides and volatile contaminants. Polycrystalline CBN is prepared from HBN by removing oxide from the surface of HBN particles to form HBN particles having a substantially oxide-free surface. The HBN particles having a substantially oxide-free surface are coated with an agent which is capable of preventing re-oxidation of the surface of the HBN particles to form coated HBN particles in a substantially oxide-free state. The coated HBN particles in a substantially oxide-free state are then converted to a polycrystalline CBN by direct conversion of HBN to CBN. Coating agents include metals, metal carbides, metal nitrides and metal borides. A preferred coating agent is titanium carbide.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.