The effect of drilling process parameters on thrust force in cotton phenolic composite

In this study, the response surface method is used to investigate the effect of drilling process parameters including cutting speed, feed rate, , drill bit point angle and drill bit relief angle on the thrust force of cotton phenol composite. This polymer-based composite material is used in various industries including electronics and aerospace industries. Investigating the effect of the drill bit relief angle as one of the effective parameters in the drilling process is one of the strength points of this research. Design of experiments was conducted using Box–Behnken method and the response surface method was used to express the trust force as a quadratic function of investigated process parameters. Variance analysis was used to check the influence of each parameter on the trust force. According to the obtained results, it was determined that cutting speed (i.e. tool revolution speed) and drill bit relief angle have the greatest and least effect on the trust force, respectively. Also, according to the quadratic equation fitted to express the trust force as a function of the investigated process parameters, the minimum trust force was obtained in the conditions of the drill bit point angle of 106.4 degrees and the drill bit relief angle of 8.4 degrees.