Investigation of tool wear and chip formation on through hole drilling of mild steel

Abstract

In drilling process at the industry, the problem that always emerges is severe wear occurs at cutting tool and poor surface finish on workpiece. This is because of improper selection of cutting parameters that affect to cutting tool condition. In this study, the experiment was performed to investigate surface roughness and chip formation on through hole drilling method using uncoated high speed steel (HSS) cutting tool in dry machining condition when drilling AISI 1018 mild steel. Surface roughness was evaluated on workpiece, where to compare surface roughness condition during the drilling process at various cutting speeds. Meanwhile, the chip formation was investigated at 8.48 m/min cutting speed. This experiment was conducted using CNC milling machine with cutting speeds 7.54,8.48, and 9.42 m/min and constant of federate at 0.15 mm/rev. Besides that, the cutting tools with 6 mm diameter was used and experiment was stopped when achieved the tool wear criteria of 0.2 mm. Based on result, value of surface roughness decrease when increase the cutting speed. At speed 8.48 m/min, 24 holes were produced. The lower number of holes produced at highest speed, 9.42 m/min with 13 holes, while highest number holes produced at lower speed, 7.54 m/min with 29 holes produced. For chip formation, the width of chips for new tool is greater than worn tool results as well as the thickness of the chip at cutting speed of 7.54 m/min. Therefore, it can be concluded that an increasing of cutting speed will result in decrease value of surface roughness that give high quality of surface produce.