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The current research aims at analyzing the machining performance measures of titanium diamond using electro-discharge machining (EDM) process. The selected control variables are peak current and pulse-on-time (Ton) while maintaining a 50% to 75% duty factor during experimental runs. The output responses considered for this operation are material removal rate (MRR), tool wear rate (TWR) and average surface roughness (Ra). A full factorial design (L16) has been employed to execute the current investigation. Analysis of variance along with overall evaluation criteria (OEC) is also carried out for determining the optimal input parametric combination. The work is further supported by mean effect plots and 3D performance plots for visual illustration of outputs. Analyzed results show that current has the most impact on MRR and Ra, while Ton has the most impact on TWR. The obtained results show MRR of 7.753 mg/min (highest), TWR of 0.02 mg/min (lowest) and Ra of 5.46 µm at the optimum parametric combination. Moreover, x-ray diffraction (XRD), scanning electron micrograph (SEM), and energy-dispersive x-ray (EDX) analysis also help in identifying different phases of material on machined work surface. [ABSTRACT FROM AUTHOR]

In the present work, machining of boron carbide (B4C) has been performed using ultrasonic machining (USM) with the same material as abrasive particles. A comparative assessment of machining of B4C with that of glass and brass has also been carried out by drilling microholes using USM. The experimentation has been conducted according to Taguchi L9 orthogonal array. The effect of feed rate, slurry concentration, and grit size has been evaluated on the performance measures such as material removal rate, overcut, circularity error, taper angle and tool wear rate. Additionally, overall evaluation criteria (OEC) has been formulated to evaluate the combined performance measures. After ANOVA feed rate became the most significant parameters affecting OEC for all the materials. The machining of B4C has been found to be possible but lacks in the machining rate in comparison with that of glass and brass. Least tool wear rate has been found in case of glass whereas minimum overcut, circularity error and taper angle have been observed for brass. The quality of the drilled holes in B4C is better as minimal surface chipping and burr formation has been observed. [ABSTRACT FROM AUTHOR]