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 TiO2 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.

Numerical modelling of ECMM of micro-dimples considering the effect of 3-phase electrolyte

“…This article discusses micro-dimple machining operation suitable for small area application, where there is no need for fabrication of mask through the machining process. A single electrode-based electrochemical micromachining is being widely used for hole drilling, 21 milling, 22, 23 micro-tools fabrication, 24 parting and structuring. 25 Single tool-based micro-texturing methodology opts from the earlier research of Patel et al 26, 27 where predesigned micro-tool is employed with zero feed at the minimum inter-electrode gap (IEG) which leads to the formation of bell-shaped micro-dimples.…”

Effect of Electrolyte Filtration Accuracy on Electrochemical Machining Quality for Titanium Alloy

“…Yang and Wang [24] investigated various electrolytes in the ECM of titanium alloys, identifying the effects of the electrolyte on spot corrosion, and proposing a dissolution mechanism. T. Mukesh [25] conducted the ECM experiments of TC4 alloy on radial overcut microporous machining in different electrolytes and found that adding EDTA to the electrolyte improved dimensional characteristics. Yang et al [26] focused on the influence of electrolyte composition on the corrosion behavior and tribological performance of polyethylene oxide coatings in TC4 alloy and another alloy, and determining optimal electrolyte choices for preparing these coatings.…”

Effect of tool rotation on the fabrication of micro-tool by electrochemical micromachining

“…2 Tungsten carbide electrodes are extensively used as micro-tools in micro-EDM and EMM. 3 Out of the above processes, electrochemical micromachining (EMM) is gaining popularity for micro-tool fabrication. It removes material by an anodic dissolution process, which produces a surface with no residual stress, 4, 5 which is disadvantageous in thermal processes like EDM and laser machining.…”