Annealing effect on the phase stability and mechanical properties of (FeNiCrMn)(100−x)Cox high entropy alloys

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review

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Original languageEnglish
Pages (from-to)2945-2950
Journal / PublicationJournal of Alloys and Compounds
Online published27 Nov 2016
Publication statusPublished - 25 Feb 2017


The effect of annealing on the phase stability and mechanical properties of (FeNiCrMn)(100−x)Cox (x = 5, 10 and 20, denoted as Cox hereafter) multi-component alloys referred to as high entropy alloys (HEAs) were investigated through annealing at 850 °C for different durations. The phase stability analyses were performed using X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Mechanical properties were characterized using hardness and tensile tests. All the investigated alloys exhibit a single face-centered cubic (FCC) phase in the as-cast state. Cr-rich sigma phase precipitated in the Co5 and Co10 alloys after being annealed for 48 h, while the Co20 alloy remains a single FCC phase. With precipitation of the hard yet brittle sigma phase, the hardness and yield strength of Co5 and Co10 alloys increase while the tensile elongation decreases. Compared with the Co5 alloy, the variation of hardness, yield strength and tensile elongation is smaller for the Co10 alloy due to a smaller volume fraction of sigma phase. The hardness and yield strength of Co20 alloy show a subtle decrease, however the tensile elongation remains almost unchanged. The present result could help to understand the phase stability and mechanical properties of this typical Co-Cr-Fe-Ni-Mn HEA system from compositional perspective.

Research Area(s)

  • Annealing, Hardness, High entropy alloys, Phase stability, Tensile property