An Experimental Investigation and Optimization on Machining Characteristics In Auxiliary Electrode Assisted WEDM of Al_Si Alloy

Abstract

Performance and quality characteristics are the two important challenges to manufacturing industries to develop environmentally friendly manufacturing processes. The present work focused on performance characteristics such as power consumption and metal removal rate (MRR) and quality characteristics such as kerf width and surface roughness in wire electrical discharge machining of (WEDM) of Aluminum-Silicon (Al-Si) alloy to improve machining efficiency. The power consumption, kerf width, surface roughness were aimed to minimize while maximizing the MRR in WEDM with and with an auxiliary electrode on top surface of workpice and also aimed to reduce surface defects such as micro cracks, micro voids and recast layer around the kerf. newlineA thin layer of copper sheet was provided as auxiliary electrode on the proposed Al-Si workpiece and experiments were conducted at four levels of current, pulse on time, pulse off time, voltage and wire tension and experimental results for the power consumption, kerf width, surface roughness and MRR were collected in WEDM with and without auxiliary electrode. Interaction effect of current along with pulse on time, pulse off time, voltage and wire tension and the responses was studied and found that the current was the most significant parameter and followed by voltage, pulse on time and pulse off time. In scanning electron microscope analysis, the micro cracks, micro voids and recast layers were found to be minimized in the WEDM with auxiliary electrode. newlineA hybrid teaching learning based optimization (HTLBO), which comprises teaching and learning based optimization (TLBO) technique and graph theory and utility concept (GTUC) was developed to improve performance of the WEDM process. The process parameters were optimized using the proposed methodology for the WEDM with and without auxiliary electrode. The proposed HTLBO methodology found an optimal working condition in WEDM without auxiliary electrode as 3 A of current, 6 ms of pulse on times,