Abstract:Wire electrical discharge machining (WEDM) is a widely employed non-traditional machining process. Metal Matrix Composites (MMCs) are newly developed materials having favourable mechanical properties like high strength, hardness, wear resistance and strength to weight ratio. In this study, experimental investigation based on the Taguchi method involving four control factors with three levels using orthogonal array L18 is reported. Taguchi orthogonal array was used to study the effect of combination of reinforcement, pulse on-time, off-time and servo voltage on Material Removal Rate, kerf width and surface finish. A6061 and A6061/Al 2 O 3 /10 p have been machined in this study. The wire electrode breakages were found during the machining A6061/ Al 2 O 3 p composite. The locations and frequency of wire breakage was studied to identify the reasons of wire breaking during machining of these materials.