Table of Contents

ABSTRACT

Micro-EDM is potentially an important and cost effective method of machining tungsten carbide (WC) and its composite (WC-Co) regardless of their hardness. Present study aims to investigate the effect of non-electrical and gap control parameters during the micro-EDM of WC-Co. In this study, the ‘electrode polarity’ and ‘electrode rotational speed’ have been considered as the non-electrical parameters. On the other hand, the ‘short’ detection parameter, ‘open’ parameter and ‘EDM control speed’ have been studied as the gap control parameters for micro-EDM. It has been found that, negative electrode polarity provides higher material removal rate (MRR), lower relative wear ratio (RWR) and better surface finish compared to that obtained using positive polarity. Besides, the MRR increases and RWR decreases with the increase of electrode rotational speed. It has also been observed that, the gap control parameters have significant influence on the sparking process, machining stability and machining characteristics during the micro-EDM of WC-Co. The identification of optimum gap control parameters can ensure a successful and stable machining of WC-Co.

Keywords: Micro-EDM, WC-Co composite, Non-electrical parameters, Gap control parameters, Machining characteristics, Machining stability.