Achieving favorable surface quality of titanium alloy during electropolishing process with recyclable alcohol-based electrolyte

The alcohol-based electrolyte exhibits excellent electropolishing properties for titanium alloys. However, its polishing effectiveness diminishes and the ability to polish is weakened or even lost after a certain duration of electropolishing. Consequently, there is a low reuse rate for these electrolytes, significantly limiting their efficiency in electropolishing. In light of this issue, the current study conducted experiments using different electrochemical dissolution times on titanium alloy immersed in NaCl-ethylene glycol electrolytes to explore the main reasons for the failure of the electrolyte. Furthermore, a novel method was proposed to restore the electropolishing ability of expired NaCl-ethylene glycol electrolyte. Subsequently, the titanium alloy was electropolished with recycled alcohol-based electrolyte, and a favorable surface quality was obtained. By this method, the surface roughness Ra of the polished titanium alloy could be improved from Ra 0.498 μm of the expired electrolyte to Ra 0.136 μm of the recyclable electrolyte.