Development of a mathematical model for the prediction of drill quality in voice-activated ultrasonic vibration assisted drilling process.

Abstract

In different industries, drilling quality play an important role in the success of operations by producing millions of quality drilled parts. The production of high-quality parts at the lowest possible cost to the manufacturer is the primary goal of contemporary process and assembly industries. To assess the quality index of drilling holes; circularity index and surface roughness are important metrics. In order to produce better drilled parts at lower prices, this study work attempts to determine the key process variables using voice acting modules to investigate the induced vibrations effects that have the greatest impact on surface roughness and circularity index in a vertical CNC drilling machine. In order to forecast the surface roughness and circularity index of drilled holes within a given operational range, a mathematical model has been proposed by adopting a coupled algorithm using design expert and statistical approach. As an experimental design technique, Response Surface Methodology with small central composite design is used to enable the evaluation of various process parameters related with machining and vibration parameters and their effects on surface roughness and circularity index. The created model is improved using statistical tools to ensure the best match to the experimental data. It has been observed with the increase of RPM and vibration frequency the surface roughness increases up to a certain limit and then decrease whereas with the increase feed the surface roughness increases. But in terms of circularity index with the increase of the process parameters the plotted graph trends under perturbation analysis shows the similar pattern CI decreases up to a certain limit and then increases.