Modeling the tool wear rate in powder mixed electro-discharge machining of titanium alloys using dimensional analysis of cryogenically treated electrodes and workpiece

Abstract

Three grades of titanium alloy TITAN 15, TITAN 21, and TITAN 31 were machined using powder mixed electric discharge machining to study the effect of cryogenic treatment and its effect on tool wear rate (TWR). Thereafter, an attempt has been made to develop a mathematical model for predicting TWR using dimensional analysis using the outcome of the Taguchi model and thermo-physical properties of tool materials. The model shows the significant role of thermal conductivity on TWR in electric discharge machining of titanium alloys. The predicted values from the developed mathematical model were validated and were found to be in good agreement with the experimental results. Microscopic investigations on selected tool samples were performed using scanning electron microscope, energy-dispersive X-ray spectrometer, and X-ray diffraction. The results showed transfer of material on the tool surface from the workpiece, dielectric, and the powder.