Feasibility study on production of Metal Matrix Composite (MMC) material for Electrical Discharge Machining (EDM) tools using Rapid Prototyping (RP) technique

Abstract

In common practice, tools for EDM have traditionally been made by machining copper or graphite to the required profile using CNC machines. Increasing the degree of complexity of any tooling design for any operations results in a corresponding increase in time and cost required. With the advent of rapid prototyping techniques, the problem of making tools with complex shapes becomes much simpler and easy. The main aim of this research was to develop new EDM electrode material through a novel approach by rapid prototyping (RP) technique. In this study, the potential application of copper (Cu) reinforced alumina (Al2O3) fabricated with various compositions as an EDM electrode was investigated. The electrodes were fabricated by Canon PIXMA IP 1800 printer and underwent sintering temperature at 85 % and 95 % melting point of copper. The EDMed workpiece was aluminium and the electrodes surface was analyzed through scanning electron microscope (SEM). Findings showed that the electrode with Cu - 0 vol. %Al2O3 composite and sintered at temperature 977°C resulted in highest metal removal rate (MRR) and lowest electrode wear rate (EWR) while Cu - 10 vol. %Al2O3 composite and sintered at temperature 977°C revealed a better surface finish than other electrodes. An increase in Al2O3 content in general will increase the hardness of tool, as a trade-off, the conductivity was reduced.