Investigation of pulsed electrochemical micro-drilling on titanium alloy in the presence of complexing agent in electrolyte

Abstract

Titanium and its alloys have excellent mechanical and chemical properties; however, these properties make the processing of titanium alloys more challenging compared with other engineering materials. Electrochemical micromachining (ECMM) is a non-conventional machining process, which removes material through anodic dissolution regardless of the material’s hardness. However, during the electrochemical machining of titanium, the formation of a passive oxide layer inhibits further material removal and deteriorates the machined surface quality. In addition, the accuracy of micromachining of titanium alloys is especially affected by the formation of electrolysis precipitates such as TiO 2 and stray current dissolution. In this study, the effect of the addition of the complexing agent to different electrolytic solutions on the radial overcut during micro-drilling of titanium alloy grade 5 (Ti6Al4V) has been experimentally studied using the in-house developed ECMM set-up. The influence of parameters such as applied voltage and different electrolytic concentration with and without the complexing agent on overcut during ECMM on Ti6Al4V of micro-holes has been studied. It has been safely concluded that the quality of micro-holes fabricated in the presence of EDTA in the electrolyte while machining is responsible for better dimensional characteristics.