High entropy alloy FeMnNiCoCr coatings: Enhanced hardness and damage-tolerance through a dual-phase structure and nanotwins
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.
Keywords
Damage tolerance, Dual phase, Hardness, High entropy alloy, Nanotwins Bias voltage, Chromium alloys, Coatings, Cobalt alloys, Entropy, Hardness, High-entropy alloys, Iron alloys, Manganese alloys, Phase structure, Substrates, Deposition process, Direct current magnetron sputtering, Dual phase, Dual phase structures, Elongated structures, Hcp transformations, Nanotwins, Substrate bias voltages, Damage tolerance
Document Type
Journal Article
Date of Publication
1-1-2020
Publication Title
Surface and Coatings Technology
Publisher
Elsevier
School
School of Engineering
RAS ID
32476
Copyright
subscription content
Comments
Sha, C., Zhou, Z., Xie, Z., & Munroe, P. (2020). High entropy alloy FeMnNiCoCr coatings: Enhanced hardness and damage-tolerance through a dual-phase structure and nanotwins. Surface and Coatings Technology, 385, Article 125435. https://doi.org/10.1016/j.surfcoat.2020.125435