Advances in Nickel-Containing High-Entropy Alloys: From Fundamentals to Additive Manufacturing.

Area of Science:

• Materials Science
• Metallurgy
• Advanced Materials

Background:

• High-entropy alloys (HEAs) are advanced materials known for exceptional mechanical properties and corrosion resistance.
• Nickel-based HEAs exhibit remarkable strength, ductility, and oxidation resistance, making them highly sought after.

Purpose of the Study:

• To review recent advancements in nickel-containing high-entropy alloys.
• To cover fundamental principles, alloy design, and additive manufacturing techniques for these materials.

Main Methods:

• Analysis of the relationship between alloy composition, valence electron concentration (VEC), and crystal structures.
• Exploration of additive manufacturing (AM) techniques (SLM, EBM, LMD) for HEA fabrication.
• Investigation of microstructural features and post-processing effects on mechanical and oxidation behavior.

Main Results:

• Additive manufacturing presents challenges like porosity and defects, but optimization strategies exist.
• Microstructure, grain size, and phase composition significantly influence mechanical properties.
• Aluminum content and VEC are critical for oxidation resistance, with protective scales forming.

Conclusions:

• Nickel-based HEAs fabricated via AM show great promise for aerospace, automotive, and energy sectors.
• Further research is needed to overcome AM challenges and fully harness the potential of these materials.