Abstract:
The study concerned with optimization of modulation-assisted drilling (MAD) operation for a difficult-tocut
material Ti6Al4 V was carried out via response surface method (RSM). Conventional drilling (CD) has
been explored for comparison purposes. Experiments have been designed according to the Central
Composite Design (CCD). The impact of machining input parameters on surface roughness (SR), machining
power consumption, and tool wear (TW) was investigated for both cases. Pilot experiments were
carried out to find out the best modulation range. Further drilling experiments were carried out varying
feed rate, spindle speed, and tool diameter. Multiple regression analysis using RSM established relationships
between these parameters and responses. ANOVA was used to develop and test the mathematical
models. The models were effective in predicting the responses for MAD of Ti6Al4 V. The optimum drilling
parameters are a tool diameter (TD) of 2 mm, feed rate (FR) of 0.030 mm/rev and spindle speed (SS) of
2176.87 rpm. SEM and EDS analyzes were performed to investigate the machined surfaces. From the
study, it can be concluded that MAD is a promising machining process for difficult-to-cut materials with
comparatively less thrust force, surface roughness and tool wear.
Abbreviations: SD: Standard deviation; SS: Spindle Speed; TF: Thrust Force; BUE: Built-Up-Edge; PRESS:
Prediction error sum of squares; TD: Tool Diameter; CD: Conventional Drilling; CV: Coefficient of variance;
MAD: Modulation-Assisted Drilling; SR: Surface Roughness; VAM: Vibration-Assisted Machining; TW: Tool
Wear; RSM: Response Surface Methodology; ANOVA: Analysis of Variance; FR: Feed Rate; SNR: Signal-to-
Noise Ratio; FW: Flank wear
