Bi-Continuous W-Rich Refractory High Entropy Alloy-Cu Composite: Toward Material Innovation of Nuclear Reactor...

Area of Science:

• Materials Science
• Nuclear Engineering
• Metallurgy

Background:

• Refractory high-entropy alloys (RHEAs) offer superior mechanical strength and irradiation resistance for nuclear applications.
• Challenges exist in integrating RHEAs with copper cooling systems due to unfavorable mixing thermodynamics.

Purpose of the Study:

• To develop a stable RHEA-copper composite using liquid metal dealloying (LMD).
• To evaluate the composite's interfacial properties, irradiation resistance, and thermal conductivity for extreme environments.

Main Methods:

• Fabrication of a WTaVTi precursor alloy with a directional dendrite-interdendrite structure.
• Reaction of the precursor alloy with molten copper at 1200 °C for 96 hours via LMD.
• Assessment of microstructure, interfacial bonding, irradiation swelling, and thermal conductivity.

Main Results:

• A stable RHEA-Cu composite interface was formed with a beneficial W-rich interlayer.
• The composite exhibited 30% less swelling under alpha-ion irradiation compared to pure tungsten.
• Thermal conductivity reached ~120 W m⁻¹ K⁻¹ at ~650 °C, surpassing pure tungsten, with a positive temperature gradient.

Conclusions:

• The LMD process is effective for creating stable RHEA-Cu composites with industrial potential.
• The developed composite material combines RHEA's radiation tolerance with copper's thermal conductivity for advanced nuclear applications.
• The study provides a strategy for designing high-performance materials for extreme environments.