Issues of gas film stability with performance characteristics in u-ECDM: A review of existing approaches and preliminary investigation on proposed stable & sustainable approach

Micro-featured devices (made of glass and its composites) are becoming increasingly necessary for Micro Electro-Mechanical Systems (MEMS) and healthcare devices with the emergence of technology. Due to limitations of existing methods, Micro Electro Chemical Discharge Machining (μ-ECDM) is an evolving technique for difficult to micro machine materials like glass. However, improper flushing and unstable electrolytic conditions in the processing zone percolates the efficacy, accuracy, and repeatability of μ-ECDM. Consequently, deteriorating the sustainability and industrial feasibility of this process. To cope up with these problems, various approaches like ultrasonic assistance, rotary mode, magneto hydrodynamic are integrated and investigated with μ-ECDM in the literature. Although these approaches achieved the intended objectives but do not assure the stability and sustainability of the process, which are essential for industrial feasibility in the present scenario. The present review has stressed upon the effects of existing approaches on gas film formation, discharge characteristics and performance outcomes. Systematic review methodology indicated the extensive usage of ultrasonic vibrations in μ-ECDM and, the studies on the stability/sustainability of μ-ECDM process are neglected. According to literature and preliminary investigation, problems pertaining to the rising electrolyte temperature and heterogeneous electrolyte concentration are the attributed reasons, which affects the stability as well as sustainability. Therefore, the present review proposed an innovative approach to achieve the stability and sustainability of μ-ECDM process by controlling the electrolytic conditions (termed as controlled-ECDM). A preliminary experimental investigation witnessed the enhancement of process performance and quality characteristics in controlled-ECDM.