A nanograins-attached and ultrathin Cu flake powder fabricated by high energy mechanical milling and dealloying

TL;DR

This paper presents a novel method combining high energy mechanical milling and dealloying to produce mass-manufacturable copper powders with unique nanostructures, specifically nanograins-attached ultrathin flakes.

Contribution

It introduces a new fabrication process for nanostructured metal powders with controllable morphology, expanding potential applications beyond nanoporous structures.

Findings

Fabrication of nanograins-attached ultrathin Cu flakes.

Microstructure analysis elucidates formation mechanism.

Process enables mass production of novel nanostructured powders.

Abstract

Metal powders with hierarchical nanostructures are always designed and fabricated by dealloying with or without combination of other manufacturing processes. However, they are mainly nanoporous metal powder and its derivations, and their monotonous nanostructures restrict their applications, so metal powders with novel nanostructures should be explored further for various applications. Herein, high energy mechanical milling and dealloying can be combined together for fabricating mass-produced metal powders with controllable nanostructures. As an example, a nanograins-attached and ultrathin Cu flake powder can be fabricated by high energy mechanical milling of a Cu-42wt.%Al powder mixture and subsequent dealloying. The dealloyed Cu powder particles have ultrathin flaky shapes with numerous Cu grains being attached to their surfaces, and the microstructure of the as-milled Cu-42wt.%Al powder particles and the dealloyed Cu particles is studied to elucidate the formation mechanism of the unique morphology of the dealloyed Cu powder.