Development and Testing of Cold Spray Cr Coatings for Accident Tolerant Fuel Program

Cold Spray technology is being developed to deposit oxidation-resistant coatings onto Zr-alloy fuel cladding to improve accident tolerance in light water reactors (LWRs). These coatings must be able to significantly improve the oxidation resistance of the cladding in high temperature (> 1100 °C) steam and air environments, while also provide improved corrosion resistance under normal operation conditions. Cold spray is a solid-state powder-based deposition process that can deposit dense, adherent coatings onto a substrate at ambient temperature and pressure and at high deposition rates. We have developed several coated cladding concepts using cold spray, including Ti₂AlC MAX phase, FeCrAl/Mo, and Cr, with pure Cr being the most promising from an industry standpoint. Results of optimization of powder and coating microstructure for achieving high coating density, adhesion, resistance to high temperature oxidation and hydrothermal corrosion as well as measurements of residual stresses in the coatings will be presented.