Effects of processing route on phase evolution and mechanical properties of CoCrCuFeNiSix high entropy alloys

Abstract

In the present study, an attempt has been made to evaluate the effect of processing route on phase evolution and mechanical properties of CoCrCuFeNiSix (x = 0, 0.3, 0.6 and 0.9 atomic ratios) high entropy alloys. The CoCrCuFeNiSix high entropy alloys were prepared through two different routes i.e., spark plasma sintering and vacuum arc melting. The X-ray diffraction results reveal face-centered cubic structure along with σ phase after spark plasma sintering and it is also observed that addition of Si favors σ phase formation. Whereas, sample papered by arc meting route showed face-centered cubic structure up to 0.6 Si content. Further increase in Si (0.6–0.9) leads to the formation of Ni3Si. Enhanced microhardness and superior wear resistance were achieved with the increase in Si content from 0 to 0.9 in both synthesis routes. However, better physical properties were obtained by spark plasma sintered samples compared to the arc melted samples due to the formation of σ phases. Furthermore, comparative analyses were performed based on the parametric approach to study the phase evolution.