Optimization of Thrust Force and Surface Roughness Using Response Surface Methodology (RSM) in Drilling of Al-30Zn Alloy

Bayraktar Ş., Hekimoğlu A. P.

Gümüşhane Üniversitesi Fen Bilimleri Dergisi, vol.10, no.3, pp.804-813, 2020 (Peer-Reviewed Journal)


In this study, Al-30Zn alloy was produced by permanent mold casting method. Drilling tests were performed after the values of hardness, tensile strength and elongation to fracture of the alloy were determined. 80x50x20 mm in dimensions workpiece was prepared from alloy ingot and drilling tests were performed with 8 mm diameter, 30° helix and 118°-point angle uncoated HSS (High speed steel) drills. Drilling tests were performed according to the experimental design obtained in response surface methodology (RSM) statistical analysis software. Independent variables were defined as cutting speed (600, 900and 1200 rev/min) and feed rate (0.05, 0.15and 0.25 mm/rev), while dependent variables were defined as thrust force and surface roughness. According to the experimental results, the statistical effect of independent variables on dependent variables was analyzed with ANOVA and optimum cutting parameters were determined. Accordingly, it was observed that the most effective independent variables on thrust force and surface roughness were feed rate and cutting speed, respectively. In addition, optimum cutting conditions according to minimum goal function were determined as cutting speed of 1200 rev/min and feed rate of 0.05 mm/rev. It was found that validation tests and statistical results were quite compatible depending on optimum cutting conditions.