Microstructure and Mechanical and Corrosion Behavior of Novel High-Entropy CoCrFeNiSiVx (x = 0.25; 0.5; 0.75; 1.0) Alloys

TL;DR

This study explores new high-entropy alloys with varying vanadium content and evaluates their structure, mechanical strength, and corrosion resistance.

Contribution

The paper introduces novel CoCrFeNiSiVx alloys and demonstrates how vanadium affects their microstructure and performance.

Findings

Higher vanadium content improves corrosion resistance and hardness in the alloys.

The CoCrFeNiSiV0.75 alloy showed the lowest friction coefficient.

Abrasive, fatigue, and oxidative wear were identified as main wear mechanisms.

Abstract

In this work, a series of novel high-entropy alloys CoCrFeNiSiVx (x = 0.25; 0.5; 0.75; 1.0) with an intermetallic compound structure was proposed. The effect of vanadium addition on the structure, as well as selected mechanical and corrosion properties, was investigated. In the case of the CoCrFeNiSiV0.25 alloy, the structural analysis revealed the formation of a dual-phase structure consisting of Fe1.812V0.907Si0.906-type and Fe5Ni3Si2-type intermetallic phases. The increase in vanadium concentration results in the crystallization of one Fe1.812V0.907Si0.906 intermetallic phase detected by the X-ray diffraction method. The increase in vanadium content had a beneficial influence on the corrosion resistance of CoCrFeNiSiVx alloys in 3.5% NaCl. The CoCrFeNiSiV alloy exhibited the lowest corrosion current density of 0.17 μA/cm2 and the highest corrosion potential of −0.228 V. The hardness of the alloys investigated increased with vanadium content, reaching 1006 HV for the equimolar alloy. In turn, the lowest friction coefficient of 0.63 ± 0.06 was obtained for the CoCrFeNiSiV0.75 alloy. The abrasive, fatigue, and oxidative wear were identified as the main wear mechanisms.

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