Unveiling a Bulk WTaV Multicomponent Alloy With Superior Thermal Properties and Manufacturability

Area of Science:

• Materials Science
• Metallurgy
• High Entropy Alloys

Background:

• Tungsten (W)-based medium and high entropy alloys (HEAs) show promise for extreme environments due to enhanced stability and mechanical properties.
• Key challenges for W-based HEAs include bulk manufacturing and inferior thermal performance compared to pure W.

Purpose of the Study:

• To develop and characterize a novel arc-cast WTaV multicomponent alloy.
• To evaluate the alloy's microstructural stability, mechanical properties, and thermal conductivity for demanding applications.

Main Methods:

• Thermodynamic and atomistic Monte Carlo simulations guided alloy design.
• Arc-casting technique used for bulk manufacturing of the WTaV alloy.
• Microhardness testing and high-temperature heat treatment assessed mechanical stability.
• Thermal conductivity measurements performed across a range of temperatures.

Main Results:

• Successfully manufactured a single-phase body-centered cubic (BCC) WTaV alloy without brittle intermetallics.
• Achieved high microhardness (∼535 HV) with minimal reduction after 24h at 1800°C, indicating excellent thermal stability.
• Exceptional thermal conductivity demonstrated (57 Wm^-1K^-1 at RT, 134 Wm^-1K^-1 at 1000°C), surpassing pure W at high temperatures.
• Observed an inverse relationship between temperature and thermal conductivity, unlike pure W.

Conclusions:

• The WTaV alloy presents a viable candidate for extreme environments, balancing manufacturability, cost, and performance.
• Its superior high-temperature mechanical stability and enhanced thermal conductivity address critical limitations of existing W-based materials.
• The alloy's unique thermal behavior and properties make it suitable for applications in nuclear fusion and aerospace.