Preparation and High‐Temperature Microplastic Forming Performance of Nano‐FeCoNi Medium‐Entropy Alloy Foils

Nanocrystalline FeCoNi medium‐entropy alloys (MEAs), characterized by their unique internal microstructure and substantial industrial application potential, often exhibit superior performance compared to conventional alloys and high‐entropy alloys. Herein, nanocrystalline FeCoNi MEAs are fabricated using an alternating current pulse electrodeposition method. The microstructure, crystallographic characteristics, and mechanical properties of the electrodeposited layers are systematically investigated. A MEA foil with a nanoscale grain thickness of 45 μm is successfully prepared. Furthermore, the foil is subjected to microbulging tests using a gas‐pressure microforming setup. The morphology and stress distribution of the deformed alloy are analyzed in detail.