The Investigation of Hole Delamination in Drilling Kevlar Composite Panel Using HSS Drill Tool

Abstract

The drilling process has been mostly used in composite panel machining to be a final product. It becomes a critical process when the composite product requires a high hole precision for the purpose of assembly and quality standard. Machining Kevlar composite is a difficult task due its hardness, fiber layer bounding and fiber orientation. The cutting condition needs to be controlled carefully to minimize the vibration, cutting temperature and hole delamination. This paper discusses the investigation of hole delamination in drilling Kevlar composite panel. The twist drill type of High-Speed Steel (HSS) drilling tool with 12 mm diameter was used to drill a 4 mm thick Kevlar composite panel. Three levels of spindle speed (1000 rpm, 1400 rpm and 2000 rpm) and three levels of feed rate (130 mm/min, 160 mm/min and 180 mm/min) were selected as the configuration of cutting condition. The hole diameter was measured and was compared to the drill tool diameter. The result of the experiment shows that the cutting condition gave significant effect to the drill hole delamination factor. The highest delamination factor was 1.36 and achieved by drilling condition with spindle speed of 1000 rpm and feed rate of 160 mm/min. The lowest delamination factor was 1.161 and achieved by drilling condition with spindle speed of 2000 rpm and feed rate of 130 mm/min.