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A novel high entropy alloy based on the CoCrFeMnNi system with substantial amounts of Al and C was studied. After cold rolling and annealing at 973-1273 K a duplex ultra-fine grained structure composed of the recrystallized fcc grains and M23C6 and B2 particles was produced. Analysis of the coarsening behavior of grains and particles growth suggested that kinetics of both was controlled by volume diffusion. The apparent activation energy of structure coarsening during recrystallization was evaluated.

In the present study, the active phases (AP) of an Fe–Ni–Co–Mn catalyst produced from SHS-intermetallics (a), a catalyst prepared via formation an intermetallic layer on a mesh surface of chromium-nickel stainless steel (b), and of a Co–Mn catalyst prepared via SHS on silica gel support (c), were isolated and characterized by SEM and XRD. The catalysts studied were highly active in the process of deep oxidation and catalysts (b) and (c) were highly active in the process of CO2 methanation as well. All AP had oxo-metallic composition and were formed from nanoscale components, but if the structure of these components for catalyst (a) was the same as on the surface of the catalyst, the structures of AP components for catalyst (b) significantly differed from the surface structures. In addition, AP sediment grain nanostructures of catalyst (c) differed from those of catalysts (a) and (b).