Special corrosion behavior of an inoculant refined Cu-Al-Mn shape memory alloy during electropolishing process

Highlights: • Inoculant refined CuAlMn SMA exhibits special corrosion behavior in electropolishing. • The corroded surface of the alloy look like a beautiful ink-washing painting. • Stress layers, rather than loosely arranged atoms, are responsible for the corrosion. • This study provides a method to pursue the distribution of inoculant particles. • This study can help us to reveal the refining mechanism of inoculants refined alloys. -- Abstract: The Cu-11.9Al-2.5Mn (wt%) shape memory alloy (SMA) refined by the Cu₅₁Zr₁₄ inoculant exhibits special corrosion behavior in electropolishing process, which makes the surface of the alloy look like a beautiful ink-washing painting. Transmission electron microscope (TEM) observation reveals that this can be ascribed to the stress layers existing near the Cu₅₁Zr₁₄/Cu-Al-Mn interfaces. Fortunately, these stress layers do not disturb the perfect lattice matching relationship between the Cu₅₁Zr₁₄ particle and the Cu-Al-Mn SMA. This study provides a simple and efficient method to pursue the distribution of inoculant particles in the refined alloys and to help us to reveal the refining mechanism.