Modeling and Analysis Of Molybdenum Di Sulphide Powder Mixed Electrical Discharge Machining Of Aisi 304 Steel

Abstract

This research dissertation presents a numerical model to predict crater geometry during powder mixed electrical discharge machining (PMEDM) process. The consequence of adding powder particles into the dielectric liquid of EDM is assessed and their influence on crater geometry (diameter and depth) is examined using pulse trains. Molybdenum di-sulphide (MoS2) powder particles of two distinct mean size viz. and#934; 40 µm and and#934; 90 nm are chosen for this study. Discharge duration, peak current, gap voltages and duty factor are taken as input variables. The input variables are varied in wide range to encompass rough to finish machining regime adopted in industry. Discharge energy, material removal rate (MRR) and surface integrity are considered as outcome measures. 2D roughness profiles, EDS, EPMA, and XRD profiles are used to assess the powder mixed electrical discharge machined (PMEDMed) surface. Further, a thorough investigation is carried out to explore the tribological characteristics of PMEDMed surfaces. In comparison with the experimental results, the proposed model predicts diameter of crater with an error of 7.77%, -15.47%, 5.82% and 6.69% for discharge duration, peak current, gap voltage and duty factor respectively for and#934; 40 µm powder; similarly 6.69%, 8.22%, 7.31% and 6.69% for and#934; 90 nm powder. Subsequently the simulated results and the experimentally measured crater depth are in good agreement for both and#934; 40 µm and and#934; 90 nm powder. Results clearly indicate that the addition of MoS2 powder into the dielectric, improves MRR by 21% for and#934; 40 µm and 84.21% for and#934; 90 nm. Better surface integrity compared to pure dielectric is achieved. The tribological characteristics demonstrated that, the PMEDMed surface offered 66% reduced coefficient of friction and 99% reduction in specific wear rate compared to the base material. newline