COMPUTATIONAL DESIGN OF CORROSION-RESISTANT Fe-Cr-Ni-Al NANOCOATINGS FOR POWER GENERATION

A computational approach has been undertaken to design and assess potential Fe-Cr-Ni-Al systems to produce stable nanostructured corrosion-resistant coatings that form a protective, continuous scale of alumina or chromia at elevated temperatures. Phase diagram computation was modeled using the Thermo-Calc (R) software and database [1, 2] to generate pseudo-ternary Fe-Cr-Ni-Al phase diagrams to help identifying compositional ranges without undesirable brittle phases. Computational modeling of the grain growth process, sintering of voids, and interface toughness determination by indentation, assessed micro-structural stability and durability of the nanocoatings fabricated by a magnetron-sputtering process. Interdiffusion of Al, Cr, and Ni was performed using the DICTRA (R) diffusion code [3] to maximize the long-term stability of the nanocoatings.