Enhanced corrosion resistance of laser-remelted Fe–Cr–B–Mo alloy through interfacial periodic layered structures in liquid aluminum

Abstract

Corrosion of liquid aluminum impedes the development of aluminum-based products and equipment. Modifying microstructures at the matrix-corrosion interface enhances alloy’s corrosion resistance. High-boron alloys, renowned for their superior corrosion resistance, are closely associated with their microstructural characteristics. This study aims to elucidate the microstructural evolution and enhanced corrosion resistance of laser-remelted Fe-Cr-B-Mo alloy, with a particular focus on the mechanisms underlying its enhanced corrosion resistance. The results reveal that the laser-remelted layer, featuring homogeneous micro-nano structures, forms continuous periodic layered structures (PLSs) across the entire interface, enhancing corrosion resistance by preventing elemental interdiffusion and pinning interfacial corrosion products. The formation mechanism of PLSs results from solid-liquid interface diffusion couples caused by thermodynamic and kinetic instabilities. Tailored micro-nano structures, coupled with continuous and full-interface PLSs, offer a novel approach to enhancing corrosion resistance against liquid aluminum, potentially facilitating the development of corrosion-resistant Fe-B alloys.