Investigation of tool wear and chip formation on peck 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 part drilled. This is because of improper selection of cutting parameter that affects to the cutting tool condition. In this study, the experiment was performed to investigate the tool wear and chip formation on peck drilling method using uncoated high speed steel (HSS) cutting tool in dry machining condition when drilling AISI 1018 mild steel. The tool wear was evaluated on cutting tool, where to compare the cutting tool condition during the drilling process at various cutting speeds. Meanwhile, the chip formation was investigated on lowest cutting speed at 7.54 m/min. This experiment was conducted using a CNC milling machine with cutting speeds of 7.54, 8.48 and 9.42 m/min and constant of feedrate at 0.15 mm/rev. Besides that, the cutting tools with 6 mm diameter was used and the experiment was stopped when achieved the tool wear criteria of 0.2 mm. Based on result, rapid wear occurs at cutting speed of 9.42 m/min with a produces 19 holes while low cutting speed of 7.54 m/min produces 41 holes. For chip formation, the width of chips for the new tool is greater than worn tool result 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 increase of tool wear that lead to various problem factor during the drilling process.