Topological Control of Liquid-Metal-Dealloyed Structures

TL;DR

This paper introduces a combined computational and experimental approach to control the topology and size of liquid-metal-dealloyed structures by adding specific elements to the melt, overcoming previous limitations.

Contribution

It demonstrates that adding certain elements to the melt can produce high-genus topologies and smaller ligaments, expanding the design possibilities of dealloyed structures.

Findings

Adding elements limits immiscible element leakage during dealloying

Bulk diffusive transport influences structure evolution

New method produces structures with desired size and topology

Abstract

The past few years have witnessed the rapid development of liquid metal dealloying to fabricate nano-/meso-scale porous and composite structures with ultra-high interfacial area for diverse materials applications. However, this method currently has two important limitations. First, it produces bicontinuous structures with high-genus topologies for a limited range of alloy compositions. Second, structures have a large ligament size due to substantial coarsening during dealloying at high temperature. Here we demonstrate computationally and experimentally that those limitations can be overcome by adding to the metallic melt an element that promotes high-genus topologies by limiting the leakage of the immiscible element during dealloying. We further interpret this finding by showing that bulk diffusive transport of the immiscible element in the liquid melt strongly influences the evolution of the solid fraction and topology of the structure during dealloying. The results shed light on fundamental differences in liquid metal and electrochemical dealloying and establish a new approach to produce liquid-metal-dealloyed structures with desired size and topologies.