Investigation of wear mechanism in drilling of PPA composites for automotive industry

Drilling is one of the most widely used processes in manufacturing and assembling parts used in the automotive industry.Drill bits wear out due to increased forces and temperatures during the drilling process. Drill wear is one of the most important problems when drilling conventional or composite materials. This reduces the quality of the hole and degrades the drill. In this study, the wear mechanism during drilling of PPA composites used in the automotive industry was investigated. Therefore, TiN-coated HSS drills were utilized in the tests. A TiN-coated HSS drill with a diameter of 5 mm and a tip angle of 118° was used to perform the drilling test. Drilling tests were performed in dry conditions on a 3-axis CNC milling machine. Three cutting speeds of 15, 20 and 25 m/min and feed rates of 0.05, 1.0 and 1.5 mm/rev were selected for the drilling conditions. Scanning Electron Microscopic (SEM) images and Energy Dispersive Spectrum (EDS) analysis were used to study the wear mechanism. As a result of the investigation, the mechanisms of abrasive wear and adhesive wear were identified. Drills also showed flank wear, corner rounding, chipping, and coating flaking. •The wear mechanisms in the drilling of PPA composites were investigated.•TiN-coated HSS drill was used in drilling process.•SEM images and EDS analyzes were used to detect wear mechanisms.•As a result of the drilling process, abrasive and adhesive wear mechanisms were determined.•Flank wear, corner rounding, chipping, and coating delamination formation were observed on the drills.