Elevated-Temperature Tribo-Corrosion Response of Eutectic High-Entropy Alloy

Area of Science:

• Materials Science
• Tribology
• Corrosion Engineering

Background:

• Elevated temperatures and tribo-corrosion accelerate structural component degradation in extreme environments.
• High-entropy alloys (HEAs) offer potential for enhanced degradation resistance over conventional alloys.

Purpose of the Study:

• To evaluate the microstructural stability and tribo-corrosion resistance of AlCoCrFeNi_2.1 eutectic HEA.
• To compare the performance of AlCoCrFeNi_2.1 HEA against duplex stainless steel 2205 under varying temperatures.

Main Methods:

• Tribo-corrosion testing of AlCoCrFeNi_2.1 HEA and duplex stainless steel 2205 in deionized water.
• Testing conducted at three temperatures: 25 °C, 50 °C, and 100 °C.
• Analysis of microstructural stability, wear rate, and coefficient of friction.

Main Results:

• AlCoCrFeNi_2.1 HEA demonstrated excellent microstructural stability and tribo-corrosion resistance across all tested temperatures.
• The HEA exhibited an order-of-magnitude lower wear rate and a lower coefficient of friction compared to duplex steel 2205.
• Both materials showed lowest wear at 50 °C, attributed to temperature-assisted passivation and stable tribological surfaces.

Conclusions:

• Eutectic HEAs, specifically AlCoCrFeNi_2.1, show superior performance in tribo-corrosion applications compared to dual-phase steels.
• These findings support the potential of HEAs for use in structural components subjected to combined thermal and tribo-corrosive conditions.
• Further investigation in industrial water chemistries is recommended.