This Small Business Innovation Research (SBIR) Phase I project will demonstrate the feasibility of depositing nc-WC/Co coatings onto high-strength steels at low temperatures while retaining superior wear resistance properties. Nanocrystalline (nc) materials have enormous potential to provide structural materials with significant property improvements over conventional coarse-grained counterparts. Progress in spray forming nc-WC/Co has been very limited with numerous unsuccessful attempts to deposit these wear resistant coatings using thermal spray equipment. These high-temperature processes are not applicable for nc-WC/Co coatings because of severe decarburization during spray deposition, owing to the high surface-to-volume ratio of nano-WC grains. This technical deficiency will be overcome in this project by integrating two novel processes, one being a solid-state spray process called Kinetic Metallization (KM) and the other a nanocrystalline powder process known as Integrated Mechanical and Thermal Activation (IMTA). Nanocrystalline WC/Co powders produced by the IMTA process will be deposited onto high-strength steels using the low temperature KM process. It is anticipated that the technology, once developed, will provide metallic components and hard-face coatings with significant property improvements over today's conventional coarse-grained counterparts.
The broader impact from this technology could be improved nanocrystalline coatings in aerospace and land-based gas turbine engines and aircraft actuator markets exceeds one billion dollars annually. All of the OEM and military repair depots for these markets are actively seeking alternative coatings to replace the environmentally hazardous processes associated with hard chrome coatings. In addition to the aerospace markets, nanocrystalline coatings will find many applications in the food processing, mining, machining, infrastructure, and transportation industries where hardface coatings with improved wear resistance will extend the life of tools and equipment while reducing chemical pollution.
