Microstructure, Mechanical Properties, and Electrochemical Corrosion Behavior of CoCrFeNiNb and CoCrFeNiV High-Entropy Alloys Prepared via Mechanical Alloying and Spark Plasma Sintering

This study investigates the microstructural evolution, mechanical behavior, and electrochemical performance of CoCrFeNiNb and CoCrFeNiV HEAs fabricated via mechanical alloying and spark plasma sintering. Microstructural analyses reveal that the alloys have a face-centered cubic (FCC) matrix with Nb-...

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Main Authors: Yan Zhu, Yiwen Liu, Zhaocang Meng, Jianke Tian
Format: Article
Language:English
Published: MDPI AG 2025-07-01
Series:Metals
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Online Access:https://www.mdpi.com/2075-4701/15/7/814
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author Yan Zhu
Yiwen Liu
Zhaocang Meng
Jianke Tian
author_facet Yan Zhu
Yiwen Liu
Zhaocang Meng
Jianke Tian
author_sort Yan Zhu
collection DOAJ
description This study investigates the microstructural evolution, mechanical behavior, and electrochemical performance of CoCrFeNiNb and CoCrFeNiV HEAs fabricated via mechanical alloying and spark plasma sintering. Microstructural analyses reveal that the alloys have a face-centered cubic (FCC) matrix with Nb-enriched Laves and V-enriched σ phases. The CoCrFeNiNb HEA exhibits superior compressive strength and hardness than CoCrFeNiV due to uniform Laves phases distribution. Fracture surface analysis reveals that at lower sintering temperatures, the fracture is primarily caused by incomplete particle bonding, whereas at higher temperatures, brittle fracture modes dominated via transgranular cracking become predominant. The research results of potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) show that both alloys exhibited superior electrochemical stability in a 3.5 wt.% NaCl solution compared to the CoCrFeNi base alloy. X-ray photoelectron spectroscopy (XPS) analysis confirms the formation of stable oxide layers (Nb<sub>2</sub>O<sub>5</sub> and V<sub>2</sub>O<sub>3</sub>) on the precipitated phases, acting as protective barriers against chloride ion penetration. The selective oxidation of Nb and V improves the integrity of the passive film, reducing the corrosion rates and enhancing the long-term durability. These findings highlight the critical role of precipitated phases in enhancing the corrosion resistance of HEAs, and emphasize their potential for use in extreme environments.
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spelling doaj-art-de5b5501431e48ac80b16da81a3a98932025-08-20T03:58:30ZengMDPI AGMetals2075-47012025-07-0115781410.3390/met15070814Microstructure, Mechanical Properties, and Electrochemical Corrosion Behavior of CoCrFeNiNb and CoCrFeNiV High-Entropy Alloys Prepared via Mechanical Alloying and Spark Plasma SinteringYan Zhu0Yiwen Liu1Zhaocang Meng2Jianke Tian3College of Education, Longdong University, Qingyang 745000, ChinaAdvanced Energy Science and Technology Guangdong Laboratory, Huizhou 516000, ChinaInstitute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, ChinaAdvanced Energy Science and Technology Guangdong Laboratory, Huizhou 516000, ChinaThis study investigates the microstructural evolution, mechanical behavior, and electrochemical performance of CoCrFeNiNb and CoCrFeNiV HEAs fabricated via mechanical alloying and spark plasma sintering. Microstructural analyses reveal that the alloys have a face-centered cubic (FCC) matrix with Nb-enriched Laves and V-enriched σ phases. The CoCrFeNiNb HEA exhibits superior compressive strength and hardness than CoCrFeNiV due to uniform Laves phases distribution. Fracture surface analysis reveals that at lower sintering temperatures, the fracture is primarily caused by incomplete particle bonding, whereas at higher temperatures, brittle fracture modes dominated via transgranular cracking become predominant. The research results of potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) show that both alloys exhibited superior electrochemical stability in a 3.5 wt.% NaCl solution compared to the CoCrFeNi base alloy. X-ray photoelectron spectroscopy (XPS) analysis confirms the formation of stable oxide layers (Nb<sub>2</sub>O<sub>5</sub> and V<sub>2</sub>O<sub>3</sub>) on the precipitated phases, acting as protective barriers against chloride ion penetration. The selective oxidation of Nb and V improves the integrity of the passive film, reducing the corrosion rates and enhancing the long-term durability. These findings highlight the critical role of precipitated phases in enhancing the corrosion resistance of HEAs, and emphasize their potential for use in extreme environments.https://www.mdpi.com/2075-4701/15/7/814high-entropy alloymicrostructurelaves phasesmechanical propertieselectrochemical corrosion
spellingShingle Yan Zhu
Yiwen Liu
Zhaocang Meng
Jianke Tian
Microstructure, Mechanical Properties, and Electrochemical Corrosion Behavior of CoCrFeNiNb and CoCrFeNiV High-Entropy Alloys Prepared via Mechanical Alloying and Spark Plasma Sintering
Metals
high-entropy alloy
microstructure
laves phases
mechanical properties
electrochemical corrosion
title Microstructure, Mechanical Properties, and Electrochemical Corrosion Behavior of CoCrFeNiNb and CoCrFeNiV High-Entropy Alloys Prepared via Mechanical Alloying and Spark Plasma Sintering
title_full Microstructure, Mechanical Properties, and Electrochemical Corrosion Behavior of CoCrFeNiNb and CoCrFeNiV High-Entropy Alloys Prepared via Mechanical Alloying and Spark Plasma Sintering
title_fullStr Microstructure, Mechanical Properties, and Electrochemical Corrosion Behavior of CoCrFeNiNb and CoCrFeNiV High-Entropy Alloys Prepared via Mechanical Alloying and Spark Plasma Sintering
title_full_unstemmed Microstructure, Mechanical Properties, and Electrochemical Corrosion Behavior of CoCrFeNiNb and CoCrFeNiV High-Entropy Alloys Prepared via Mechanical Alloying and Spark Plasma Sintering
title_short Microstructure, Mechanical Properties, and Electrochemical Corrosion Behavior of CoCrFeNiNb and CoCrFeNiV High-Entropy Alloys Prepared via Mechanical Alloying and Spark Plasma Sintering
title_sort microstructure mechanical properties and electrochemical corrosion behavior of cocrfeninb and cocrfeniv high entropy alloys prepared via mechanical alloying and spark plasma sintering
topic high-entropy alloy
microstructure
laves phases
mechanical properties
electrochemical corrosion
url https://www.mdpi.com/2075-4701/15/7/814
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