Abstract: The invention relates to a process for brazing refractory particles, notably tungsten carbide grits, onto a substrate such as a tool blank to provide an armor coating or a cutting edge thereon, which process comprises applying to the substrate a brazing material, a particulate refractory material to be brazed onto the substrate and a binder composition; and connecting the substrate to a source of an electric current to cause the current to flow through the substrate whereby the substrate is heated to sufficient temperature to cause the brazing material to fuse. The invention also provides apparatus for carrying out the invention.