Cold Spray Coatings

Cold spray coatings are a variation of thermal spray coatings. Unlike “traditional” thermal spray coatings, cold spray coatings do not require the coating material to be heated to high temperatures. Instead, the coating material, usually a metal or alloy in powdered form, is accelerated to speeds as high as 900 m/s via a gas jet and sprayed onto the substrate. The powder does not melt; instead, the high speed and pressure push the material to critical velocity. The kinetic energy of this acceleration causes the solid particles to deform plastically and bond metallurgically to form a coating. The resulting coating forms a strong bond with the coated surface, and dense layers of coating can be formed. A range of metals, alloys, and other materials can be used effectively in cold spray coating. Common coating materials include aluminum, titanium, copper, tantalum, inconel, stainless steel, and nickel. The material used will depend on the desired properties of the finished coating—wear resistance, corrosion resistance, improved lubricity, and other considerations all affect the choice of material. The