Elevated temperature corrosion resistance of additive manufactured single phase AlCoFeNiTiV0.9Sm0.1 and AlCoFeNiV0.9Sm0.1 HEAs in a simulated syngas atmosphere

Abstract

High entropy alloys have attracted great interest due to their great stability and exceptional mechanical properties. Due to growing demand of novel engineering materials, which can endure harsh corrosive atmospheres, HEAs have been studied extensively to meet the demands of challenging industrial environments. Current manufacturing techniques of HEAs include arc-melting or spark plasma sintering, which are limited by factors such as high energy, grain refinement, alloying, and size limitations. In this study we report elevated temperature corrosion behavior of two new HEAs AlCoFeNiTiV0.9Sm0.1 and AlCoFeNiV0.9Sm0.1, produced by laser-based additive manufacturing, which offers high freedom of design, fast prototyping, and rapid quenching rates that are ideal for many industrial applications. These alloys were tested in corrosive syngas atmosphere at elevated temperatures to explore their applicability in such harsh environments. Phase analysis results indicated the presence of a single FCC phase in these HEAs with no major surface cracks after enduring such corrosive atmospheres. These alloys exhibited good corrosion resistance as revealed by electrochemical testing methods. CALPHAD and DFT simulations were also performed to reveal the phase stability and crystal structures to further corroborate our experimental results.