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The sliding wear behaviour of CoCrFeMnNi and AlxCoCrFeNi high entropy alloys at elevated temperatures
journal contributionposted on 2019-06-15, 00:00 authored by Jithin JosephJithin Joseph, Nima Haghdadi, Karl Shamlaye, Peter HodgsonPeter Hodgson, Matthew BarnettMatthew Barnett, Daniel FabijanicDaniel Fabijanic
High entropy alloys (HEAs) show promise as materials for structural applications, even at elevated temperatures. However, their wear behaviour over a wide range of temperatures has not been extensively studied. CoCrFeMnNi and AlxCoCrFeNi HEAs were subjected to pin-on-disc dry sliding wear at temperatures between 25 °C and 900 °C against an alumina ball, and the tribological performance benchmarked against AISI 304 and Inconel 718. A detailed characterisation of the wear tracks using electron microscopy and surface profilometry revealed a transition in wear mechanism from abrasive wear at room-temperature to oxidative and delamination wear above 600 °C. The wear performance of the HEAs, AlCoCrFeNi in particular, is substantially enhanced with increasing temperature, surpassing that of Inconel 718 at 900 °C. The enhanced wear performance of the HEAs above 600 °C is attributed to the formation of a compact oxide scale in the contact region, and relative subsurface strengthening in the form of a fine-grained recrystallised structure containing precipitation hardening phases.
Pagination32 - 44
LocationAmsterdam, The Netherlands
Publication classificationC1 Refereed article in a scholarly journal
Copyright notice2019, Elsevier B.V.
High entropy alloysPin-on-disc wear testingMicrostructureHigh-temperature sliding wearOxide scaleWear mechanismScience & TechnologyTechnologyEngineering, MechanicalMaterials Science, MultidisciplinaryEngineeringMaterials ScienceMECHANICAL-PROPERTIESTRIBOLOGICAL BEHAVIORDYNAMIC RECRYSTALLIZATIONOXIDATION BEHAVIORSIGMA-PHASEFRICTIONDEFORMATIONPERFORMANCEMechanical Engineering