Method of coating a silicon or silicide substrate

Abstract

Energy, such as from one or more lasers, is directed at the surface of a substrate to mobilize and vaporize a constituent element (e.g., carbide) within the substrate (e.g., steel). The vaporized constituent element is reacted by the energy to alter its physical structure (e.g., from carbon to diamond) to that of a composite material which is diffused back into the substrate as a composite material. An additional secondary element, which can be the same as or different from the constituent element, may optionally be directed (e.g., sprayed) onto the substrate to augment, enhance and/or modify the formation of the composite material, as well as to supply sufficient or additional material for fabricating one or more coatings on the surface of the substrate. The process can be carried out in an ambient environment (e.g., without a vacuum), and without pre-heating or post-cooling of the substrate. The process is truly heteroepitaxial, and is suitable for treating substrates of complex geometries, and coating all sides of such substrates either evenly or selectively. The process may also be used as an adjunct to conventional CVD-type processes, to eliminate the need for heating the substrate to high temperatures. Articles formed by the disclosed processes are described, including three-dimensional objects.