Optimization of drilling parameters using Taguchi technique and response surface methodology (RSM) in drilling of AISI 304 steel with cryogenically treated HSS drills

In this study, the effects of cryogenic treatment and drilling parameters on surface and hole quality were investigated in the drilling of AISI 304 stainless steel under dry drilling conditions. The control factors to provide better surface roughness (Ra) and roundness error (Re) were determined using the Taguchi method. RSM was also used to determine interactions among the control factors. In addition, analysis of variance was employed to determine the most significant control factors on the surface roughness and roundness error. Three drill categories (conventional heat treatment—CHT, cryogenic treatment—CT, cryo-tempering—CTT), cutting speeds, and feed rates were considered as control factors, and an L27\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\text{ L }_{27}$$\end{document} full factorial design with a mixed orthogonal array was selected for experimental trials. As a result, it was found that the feed rate and cutting speed were the most significant factors on the surface roughness and roundness error with percentage contributions of 83.07 and 64.365 % respectively. The predictive quadratic models were derived by the RSM to obtain the optimal surface roughness and roundness error as a function of drilling parameters and heat treatments applied to the drills.