Graded Surface Modification Of Alloys For Containment Of Chloride Molten Salts.

Investigators at the University of Arizona (UofA), and its development partners, Hewlett Packard Inc. (HP) and Helicon Corp., propose to arrest corrosion of high-temperature metal alloys used in molten chloride salts at 800C by a new process for modifying the alloy surfaces. The new process uses the additive manufacturing capabilities compatible with HP 3D Metal in layered compositions combined with Helicon's technology for making graded compositions of disordered perovskites inter-diffused in the outermost micrometer of an alloy’s surface terminated with an inert refractory metal/metal oxide dyad. The latter feature used by Helicon both improves corrosion performance and will allow for unique corrosion-testing scenarios. The project outcome will be improved integrity of protective surface layers on selected alloys. The UofA will quantify the corrosion protection. The reactive thin film fabrication and surface modification capabilities of Helicon Corp. and the molten salt handling and corrosion testing capabilities at the Gervasio labs at the UofA, will allow powder metallurgy alloys, and resulting components, to be compatible with HP's 3D additive manufacturing process so as to be qualified for service in molten chloride salts in the 700-800C range necessary for high-efficiency, sc-CO2 turbine operation utilizing CSP, as well as to have profound implications in other generation, hydrogen chemical cycles, and various manufacturing areas.