Materials with multicomponent ultrafine microstructures are increasing interest for use in cermets and metal matrix composites. This project suggests a new approach to ultrafine microstructrues and to a novel process for their preparation. The process involves electroless plating of a metal on colloidal nuclei. Silver-tin oxide for use in electrical contacts is an example of the kind of product which might be made by the new process. The principles of accretion of a dense coating on colloidal nuclei is the basis for this study. Electroless plating might be used to coat oxides, metals, or in general, colloidal particulates with a second metal. The only limits on the second metal are that its salts must be soluble and that they can be reduced to metal from solution. Microstructural control in the range of 5 to 100 nm should be possible. This control is demonstrated in the silver-tin oxide system.
