Aluminium powder mixed rotary electric discharge machining (PMEDM) on Inconel 718

摘要

The rotary tool is a recent innovation of PMEDM. Aluminium oxide (Al_2O_3) powder with a particle concentration of 0.5-1.5 gm/l was added into the dielectric to study improved machining performance. Inconel 718 was machined using copper-tungsten electrode with tool rotation about 300 rpm. Experiments were designed using Taguchi's three-level L_(18) orthogonal array. A mathematical model is developed to correlate the influences of these variables such as Peak current (I_p), Sparking gap (V), Pulse on time, (T_(on)), duty cycle and slurry concentration on MRR. A mean effect plots are generated to develop correlation between the influences of these variables such as Material Removal Rate, Tool Wear Rate, Surface Roughness and Heat affected zone. Recast layer affect means by Scanning Electron Microscopy (SEM).