High entropy alloy FeMnNiCoCr coatings : Enhanced hardness and damage-tolerance through a dual-phase structure and nanotwins

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

3 Scopus Citations
View graph of relations

Author(s)

  • Chuhan Sha
  • Zhifeng Zhou
  • Zonghan Xie
  • Paul Munroe

Related Research Unit(s)

Detail(s)

Original languageEnglish
Article number125435
Journal / PublicationSurface and Coatings Technology
Volume385
Online published4 Feb 2020
Publication statusPublished - 15 Mar 2020

Abstract

Three FeMnNiCoCr high entropy alloy (HEA) coatings were deposited onto M2 steel substrates using a direct current (DC) magnetron sputtering system under a range of substrate bias voltages (−20 V, −60 V and −120 V). The microstructure transformed from a fine elongated structure to coarse V-shaped columnar grains with increasing substrate bias voltage. A high density of nanotwins, together with the presence of a partial fcc-to-hcp transformation, was observed in the coating deposited at −120 V. This was attributed to the introduction of stacking faults whose presence was promoted by preferential re-sputtering effects during the deposition process. A high hardness value of ~9.1 GPa, accompanied by exceptional damage-tolerance, was achieved in the coating deposited at −120 V. Here, the formation of nanotwins and the dual-phase structure was found to contribute to this remarkable combination of hardness and resistance to plastic deformation.

Research Area(s)

  • Damage tolerance, Dual phase, Hardness, High entropy alloy, Nanotwins