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

Abstract

Nowadays, the problem of cutting tool failures becomes important in manufacturing industries. After certain working time at production, tool wear occurs and cutting tool become dull and required a changing. This is because inaccurate selection parameters affect the cutting tool condition. In this study, the experiment was performed to investigate the tool wear occurs in through hole drilling process using various cutting speed in dry machining. Other than that, to study chip formation produce on lowest cutting speed at 7.54 m/min. This experiment was conduct using CNC milling machine with cutting speed 7.54, 8.48, 9.42 m/min and constant feedrate at 0.15 mm/rev. Moreover cutting tools 6 mm diameter was used to drill on AISI 1018 mild steel workpiece until tool wear criteria achieved 0.2 mm. For tool wear measurement, LEICA EZ4 Microscope was used to evaluate the flank wear and types of chip formation produce were examined using Scanning Electron Microscope (SEM). As a result, on 9.42 m/min cutting speed was recorded as rapid wear which produces 13 holes in 4.6 minutes while at low cutting speed, 7.54 m/min produce 29 holes in 11.6 minutes. For chip formation the thickness of chips for new tool is thicker than worn tool result as well as for width of the chip at cutting speed 7.54 m/min. Therefore, conclusion from this experiment, increasing of cutting speed will result in increase of tool wear that lead to many problem factors during the drilling process.