COLD SPRAY COATED METAL MATRIX NANO-COMPOSITE SURFACE LAYERS ON INCONEL 617

Molten salt reactors (MSRs) operate under the extreme environments of high temperatures ≥ 800 °C, corrosive salts (molten chloride or fluoride), and neutron irradiation. ASME Boiler and Pressure Vessel Code permitted alloys, though exhibit excellent creep properties well above 800 ºC, cannot be considered as structural materials for MSRs, because they are susceptible to preferential corrosion in the presence of molten salts. GMT proposes to develop surface coated Inconel 617 bimetallic systems withstanding creep deformation and molten salt corrosion at temperatures at 800°C. Surface coatings proposed are metal matrix nano-composites (MMNC) compositions comprising of nano-particle reinforcements, namely, NixWy in a pure Ni matrix. The coatings will be deposited applying a solid-state cold spray method with mechanically alloyed ball milled powder feedstock. Coated samples will be thermally aged at 800°C for 500h. The thermally aged samples will be tested for their molten salt corrosion resistance as well as creep deformation and related to the metallurgical test results. The outcome of the proposed research will help building more sustainable commercial MSRs. There is a huge market for such MSRs worldwide and therefore the proposed technology is highly marketable. Successful completion of this research will help near-term deployment of MSRs. Development of efficient nuclear reactors will provide electricity at a cheaper rate and reduce the cost of energy per unit and will benefit the public at large.