| 摘要 |
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 particulate phase in the matrix. In another embodiment, ceramic particles are clad-coated with selected metals so that they can be used in ceramic-metal matrices, thereby producing systems wherein the components are uniformily didpersed throughout the system.
|
