2026 Doblin Cold Spray Coating Resistance

Cold spray deposition was investigated as a candidate technology for producing corrosion- and abrasion-resistant coatings for deep borehole nuclear waste disposal canisters. Commercially pure grade 2 Ti, Cu, Cu-1 wt.% alumina, and Inconel 625 were deposited on AISI C1020 steel with thicknesses between 0.9 and 3.2 mm. Coating adhesion to steel was generally poor under nitrogen propellant but improved when the initial layer was deposited using helium. All coatings exhibited residual porosity. Post-spray heat treatments were applied to reduce open porosity: laser glazing for Ti and Inconel 625 and furnace heat treatment (350 /C176 C, 1 h in air) for the Cu-based coatings. Laser treatment significantly refined the microstructure and reduced open porosity in the Ti coatings. Electrochemical testing in 0.1 M NaCl confirmed that corrosion resistance increased markedly with coating thickness and was substantially higher for Ti and Inconel 625 than for the Cu-based coatings. Furnace heat treatment enhanced corrosion resistance by approximately one order of magnitude, whereas laser glazing improved performance by roughly two orders of magnitude. Abrasion resistance (ASTM G65-00) decreased in the order: Inconel 625 > Cu + alumina > Cu > CP2-Ti. These results emphasize the critical role of eliminating open porosity to achieve high corrosion resistance in cold-sprayed coatings, while also identifying strategies for improving abrasion resistance in coatings intended for deep borehole disposal applications.