A study aimed at minimizing delamination during drilling of CFRP composites

The aim of this study is to present the methodology of Taguchi optimization technique for minimizing the delamination at the entrance of holes in high speed drilling of carbon fiber-reinforced plastics (CFRPs). The drilling process parameters evaluated are spindle speed, feed, and point angle. The experiments were performed as per Taguchi’s L₂₇ orthogonal array using cemented carbide (K20) twist drills. The defects observed at the entrance of drilled holes of CFRP plates were measured and the delamination factor was computed for each trial of the orthogonal array. The analysis of means (ANOM) and analysis of variance (ANOVA) were employed to determine the optimal process parameter levels and to analyze the effect of parameters on delamination factor. The confirmation tests with the optimal levels of parameters were carried out to illustrate the effectiveness of Taguchi design. The optimization results indicate that point angle is the most significant factor followed by feed and spindle speed. The results also highlight the importance of employing the higher speeds to minimize the delamination defects.