Influence of duty factor on the die-sinking Electrical Discharge Machining of high-strength aluminum alloy under rough machining

the use of high-strength aluminium alloys as material for injection molding tools to produce small and medium batches of plastic products as well as prototyping molds is becoming of increasing demand by the tooling industry. these alloys are replacing the traditional use of steel in the cases above because they offer many advantages such as very high thermal conductivity associated with good corrosion and wear resistance presenting good machinability in milling and electrical discharge machining operations. unfortunately there is little technological knowledge on the electrical discharge machining (edm) of high-strength aluminium alloys, especially about the amp 8000 alloy. the duty factor, which means the ratio between pulse duration and pulse cycle time exerts an important role on the performance of edm. this work has carried out an experimental study on the variation of the duty factor in order to analyze its influence on material removal rate and volumetric relative wear under roughing conditions of edm process. the results showed that high values of duty factor are possible to be applied without bringing instability into the edm process and with improvement of material removal rate and volumetric relative wear.