An investigation of energy utilization behavior on borosilicate glass through heating and stirring of the electrolyte in electro-chemical discharge machining

Owing to its non-conducting nature, Through Glass Vias (TGV) is a new paradigm to reduce the losses in high-frequency transmission systems. However, due to brittleness and non-conducting nature, micro-machining of glass is challenging. In the backdrop of limitations of the existing processes, Electro-chemical Discharge Machining (ECDM) is an evolutionary micro-machining process for brittle and non-conducting materials, like glass. ECDM is a hybrid of electro-chemical and electro-discharge processes. During machining in ECDM, poor flushing coupled with poor replenishment of electrolyte deteriorates the Energy Utilization Behavior (EUB), particularly in hydrodynamic regime. Therefore, the present article deals with a novel approach (using a magnetic stirrer) of Temperature-assisted ECDM (termed as T-ECDM) to improve the energy utilization behavior in the micro-machining of borosilicate glass. The T-ECDM approach has the capability to control the temperature and stirring rate of the electrolyte. The Machining Rate (MR) as well as Aspect Ratio (AR) of micro-hole are considered as the desirable performance indicator, while Tool Wear Ratio (TWR) and Heat-Affected Zone (HAZ) are considered undesirable performance indicator of EUB. The experimental investigation indicated the improvement in Overall Energy Utilization Index (OEUI) by T-ECDM as compared to ECDM. The morphological, composition analysis, and surface profiles of micro-hole witnessed the improved flushing and etching in T-ECDM than ECDM that resulted in better surface finish of the micro-hole. It implies better energy utilization behavior in terms of surface characteristics also.