Abstract: A new family of chromium boride coatings having excellent adhesive wear and corrosion resistance is disclosed. The coatings comprise hard, ultrafine, chromium boride particles dispersed in a metal matrix, the particles having an average particle size of less than one micron and constituting less than about 30 volume percent of the coating, the balance being metal matrix. The metal matrix may be composed of nickel or a nickel base alloy containing a metal selected from the group consisting of chromium, silicon and iron. The coatings may be prepared by a process which comprises depositing a mechanically blended powder mixture of chromium metal or a chromium alloy or mixture of both, and a boron-containing alloy onto a substrate and then heat treating the as-deposited coating. The heat treatment effects a diffusion reaction between the deposited elements resulting in the formation of ultrafine particles of chromium boride dispersed in a metal matrix.

Abstract: A new family of transition metal boride coatings having excellent wear and corrosion resistance is disclosed. The coatings comprise hard, ultrafine, transition metal boride particles dispersed in a metal matrix, the particles constituting from about 30 to about 90 volume percent of the coating, the balance being metal matrix. The average size of the particles ranges from about 0.5 to about 3.0 microns. The metal matrix contains at least one metal selected from the group consisting of nickel, cobalt and iron. The coatings may be prepared by a process which comprises depositing a mechanically blended powder mixture of a transition metal and a boron-containing alloy onto a substrate and then heat treating the as-deposited coating. The heat treatment effects a diffusion reaction between the deposited elements resulting in the formation of ultrafine particles of a transition metal boride dispersed in the metal matrix. The coating can be deposited onto the substrate using any of the known deposition techniques.

Abstract: A new family of titanium carbide/tungsten boride coatings having excellent wear and corrosion resistance is disclosed. The coatings comprise hard, ultrafine, titanium carbide particles and tungsten boride precipitates dispersed in a metal matrix, the two phases constituting from about 30 to about 80 volume percent of the coating, the balance being metal matrix. The metal matrix contains at least one metal selected from a group consisting of nickel, cobalt and iron. The coatings may be prepared by a process which comprises depositing a mechanically blended powder mixture composed of separate components including a first component containing tungsten carbide and a second component containing boron and at least one metal selected from the group consisting of nickel, cobalt and iron, the powder mixture including titanium in the first or second component or in a separate third component, at least one of the first, second or third components having a melting point below about 1200.degree. C.