Study of the EDM process effects on Aluminum alloys

Aluminum alloys offer many machining advantages such as excellent machinability and finish degree, elevated thermal exchange, reduction of weight. Till now aluminum moulds have been employed only for preproduction; with the new alloys Al 2219 and Al 7050, which have outstanding properties, we can think about medium productions of plastic components obtained by injection molding. Electro Discharge Machining is used for the machining of complex shapes typical of plastic injection moulds. In order to evaluate the machinability of these new alloys, some EDM tests have been planned. Comparison tests have also been done on Al 7075, an alloy of common employment for preproduction moulds, to have precise control data. The tests allowed understanding the correlations among process parameters, dimensional tolerances, surface finish and electrode wear. Moreover, the electrodes and the machined surfaces have been observed at the optical- and scanning electron microscope (OM, SEM) to understand the EDM mechanisms.