Method for clad-coating refractory and transition metals and ceramic particles
US5070591A · kind A · utility
Inventors
Key dates
| Filing date | Jan 22, 1990 |
| Grant date | Dec 10, 1991 |
| Priority date | — |
| Expiry date | Jan 22, 2010 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T29/49986
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
Metal and ceramic particles of various morphologies are clad with a coating from the transition metal group consisting of silver, gold, copper, nickel, iron, cobalt, aluminum etc., or combinations thereof, to provide improved coated particles for microelectronics or metal matrix composites or other uses. Refractory metal precursor core particles, such as tungsten, molybdenum, niobium and zirconium, as examples, are provided from a composite of tungsten and copper, for example, made by pressurizing and infiltrating or liquid phase sintering of molten copper into a porous tungsten skeleton. Precursor chip particles derived from a tungsten impregnated billet are used as starter particles which may be further enhanced by cogrinding in an attritor ball mill with smaller copper particles to thereby produce an enhanced copper clad-coating of tungsten particles with predetermined percent by weight of copper and tungsten content. The resulting particles exhibit improved electrical and thermal expansion coefficient matching properties for use on microelectronic ceramic substrates and when used for metal matrix composition, provides more uniform distribution of the dispersed strengthening par…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.