Electro-discharge machining of metal matrix composites - a review

Abstract

Influence of reinforcement content and machining process parameters on material removal rate, electrode wear rate and surface roughness is reviewed extensively from open literature during electro-discharge machining of aluminium based metal matrix composites. Results indicate increase of reinforcement content and their particle size affects the material removal rate, electrode wear rate and surface roughness adversely. Increase in discharge current causes an increase of electrode wear rate and surface roughness. Material removal rate and electrode wear rate increase or decrease with the increase of pulse-on current and pulse-off current, which depend on material processing parameters and other machining conditions; however, surface roughness increases on increasing the pulse-on time. Increase in flushing pressure effects all the three machining quality characteristics favourably.