Effects of drilling parameters on drill bit wear of ASTM A36 steel

Abstract

Drilling is a crucial process in metal manufacturing, with drill bits being key tools for creating holes in workpieces. During drilling, wear of the drill bits occurs inevitably. Several factors affect the wear of drill bits, such as materials, workpieces, and drilling parameters. The impact of these parameters on wear is investigated to understand the effects of drilling parameters on drill bit wear. This study used a diameter of 6 mm of uncoated high-speed steel drill bits to create the hole with 30 mm depth on ASTM A36 steel. The drilling was performed utilizing the DMG Mori DMU-50 5-axis drilling machine at three different levels of spindle speed (800, 1100, and 1400 rev/min) and feed rate (120, 135, and 150 mm/min). The sensor force dynamometer measured the thrust force and the cutting torque during drilling. However, many types of wear occur on drill bits during drilling. This research investigates only flank wear on the cutting edge of drill bits. The flank wear on the drill bits was measured with the overlap image technique using an Olympus SZ61 stereo microscope with a C-P3 OPTIKA digital camera. The results showed that adjusting drill parameters to increase the feed per revolution may result in a higher drill bit flank wear rate. Additionally, to quantify the wear of the drill bit based on the number of holes drilled, both the feed per revolution and the cutting distance per hole must be considered.