Effect of Boron Carbide (B4C) Additive during Micro-Electrical Discharge Machining of Ti-6Al-4V Alloy

Micro-electrical discharge machining (μEDM) deals with micro dimensional material removal from the work sample due to the repetitive spark discharge between the micro-tool electrode and the workpiece. In the present paper, an attempt has been made to machine through micro-holes on Ti-6Al-4V superalloy plates to investigate the effect of mixing of Boron Carbide (B₄C) powder additive in kerosene dielectric. A detailed comparative study has been made showing the effect on micro-ED machining criteria i.e. material removal rate (MRR), tool wear rate (TWR), overcut (OC) and taper by varying two most influencing micro-EDM process parameters i.e. peak current and pulse-on-time keeping other parameters such as flushing pressure, duty ratio, gap voltage, etc. as constant. It has been found that B₄C powder can enhance material removal rate while it can reduce tool wear rate. Analyses have also been done showing some optical and SEM micrographs of the micro-tool electrode tips as well as machined micro-hole walls to study the micro-hole surface features during experimentation.