Method for the production of metal-carbon composite powders

#1. Field of the Invention

#The present invention relates to metal-carbon composite powders and to methods for producing such powders, as well as products and devices incorporating the composite powders. The powders are preferably produced by a spray conversion process.

#2. Description of Related Art

#FIG. 1 is a process block diagram showing one embodiment of the process of the present invention.

#FIG. 2 is a side view in cross section of one embodiment of aerosol generator of the present invention.

#FIG. 3 is a top view of a transducer mounting plate showing a 49 transducer array for use in an aerosol generator of the present invention.

#The present invention is generally directed to metal-carbon composite powders and methods for producing metal-carbon composite powders. The invention is also directed to novel products and devices fabricated using the composite powders. As used herein, metal-carbon composite powders or metal-carbon composite particles are those that include within the individual particles at least a first metal phase, such as a pure metal or a metal alloy, and a carbon phase. The particles preferably include more than a trace amount of carbon, such as at least about 3 weight percent carbon. The powders of the present invention are not mere physical admixtures of metal particles and carbon particles, but are comprised of particles that include both a metal phase and a carbon phase.

#In one aspect, the present invention provides a method for preparing a particulate product including a metal-carbon composite. A feed of liquid-containing, flowable medium, including at least one precursor for the desired particulate product, is converted to aerosol form, with droplets of the medium being dispersed in and suspended by a carrier gas. Liquid from the droplets in the aerosol is then removed to permit formation in a dispersed state of the desired composite particles. In one embodiment, the particles can be subjected, while still in a dispersed state, to compositional or structural modification such as crystallization, recrystallization or morphological alteration of the particles. The term powder is often used herein to refer to the particulate product of the present invention. The use of the term powder does not indicate, however, that the particulate product must be dry or in any particular environment. Although the particulate product is typically manufactured in a dry state, the particulate product may, after manufacture, be placed in a wet environment, such as in a paste or slurry.

#The process of the present invention is particularly well suited for the production of finely divided composite particles having a small weight average size. In addition to making particles within a desired range of weight average particle size, the particles may advantageously be produced with a narrow size distribution, thereby providing size uniformity that is desired for many applications.