Work

Coupled effects of morphology/length scale of the microstructure and microsegregation on the corrosion behaviour of a single-phase Zn-1wt%Cu alloy

Year: 2025

Type: article

Abstract: Zn-Cu alloys are promising for biomaterials due to their unique properties. Unlike most metallic alloys, Zn-Cu exhibits a partition coefficient greater than 1, leading to solvent segregation. This study aims to explore how microsegregation and cellular microstructure affect the corrosion behaviour of a Zn-1wt%Cu alloy. Three specimens, with cellular spacings of approximately 8, 16, and 32 µm, were extracted from a directionally solidified casting. Electrochemical Impedance Spectroscopy and Potentiodynamic Polarization techniques were used to assess the corrosion performance in NaCl solutions. The results showed that coarser cellular structures demonstrated higher corrosion resistance, evidenced by greater charge transfer resistances and lower current densities. Corrosion initiated at the Cu-poor cellular boundaries, acting as anodic regions, and became more severe in finer microstructures. In contrast, larger cells with fewer boundaries exhibited less generalised corrosion, confirming that microstructural coarsening improves corrosion resistance.

Source: Next Materials

DOI: 10.1016/j.nxmate.2025.100698