Ultralight High-Entropy Nanowire Scaffolds for Extreme-Temperature Functionality

TL;DR

This paper presents ultralight, high-entropy nanowire scaffolds that combine configurational entropy and structural porosity to achieve high-temperature functionality at ultralow densities, suitable for extreme environments.

Contribution

It introduces entropy-architected nanowire metamaterials with hierarchical structures that maintain metal-like properties at densities below 1% of bulk metals, a novel approach for lightweight high-temperature materials.

Findings

Achieved densities below 1% of bulk metal.

Retained disordered face-centered-cubic phase at ultralow density.

Exhibited Curie temperatures exceeding 1000 K.

Abstract

High-entropy alloys (HEAs) combine compositional disorder with exceptional functional tunability, yet their inherently high-density limits use in lightweight systems. Here, we introduce entropy-architected nanowire metamaterials, a class of materials that couple configurational entropy with structural porosity to achieve metal-like functionality at ultralow density. FeCoNiCrCu HEA nanowires were electrodeposited into porous templates and freeze-cast into three-dimensional ``bird`s-nest`` scaffolds with densities below 1 $\%$ of the bulk metal. The resulting architectures retain a disordered face-centered-cubic phase, exhibit Curie temperatures exceeding 1000 K, and deliver thermal diffusivity ($\approx0.211$ mm$^2$ s$^{-1}$) comparable to titanium alloys. Structural and spectroscopic analyses reveal nanoscale Cu segregation that enhances magnetic ordering and thermal stability. These findings demonstrate that configurational entropy and architectural hierarchy can be co-engineered to yield lightweight, high-temperature functional materials for extreme-environment applications.