Selection of a Suitable Ethylene Glycol-based Mixed Electrolyte for Electrochemical Micro-drilling of Ti6Al4V

Titanium-based alloys have a wide range of applications across various sectors, including aerospace, automotive, and biomedical fields, due to their high-temperature resistance, tensile and compressive strength, corrosion resistance, and biocompatibility. Recently, miniaturized products made from Ti6Al4V have gained popularity in the healthcare industry for various types of implants and surgical devices. Electrochemical micromachining can address challenges associated with manufacturing such miniaturized products. However, micro-machining Ti6Al4V presents unique difficulties, particularly in selecting a suitable electrolyte that preserves the surface features of the material. To find the best electrolyte combination for micro-machining, several electrolyte mixtures were tested. It was found that combining sodium bromide (NaBr) and sodium chloride (NaCl) in specific proportions with ethylene glycol minimizes the shortcomings typically associated with each individual electrolyte, such as pitting and stray corrosion, while also improving the machining rate. The study concluded that the optimal electrolyte for the micro-machining process is a mixture of EG, 0.25 M NaBr, and 0.75 M NaCl.