Electropolishing of a Nickel–Titanium–Copper Shape Memory Alloy in Methanolic Sulfuric Acid

Abstract
Electropolishing of NiTiCu shape memory alloy was performed in methanolic sulfuric acid as a surface processing method. The current investigation, using a rotating disk electrode, aims at identifying appropriate electropolishing conditions for this alloy based on understanding the underlying mechanism. The influence of temperature, rotation rate, and sulfuric acid concentration ( or ) was quantified. Electropolishing in methanolic is solely mass-transport-controlled, while a mixed control is found for the methanolic . This behavior is different from that of the binary NiTi alloy. From the electrochemical perspective, a methanolic solution is more suitable for electropolishing NiTiCu. The activation energy for electrodissolution is .