The impact of cutting speed and feed rate on tool wear and surface damage during the milling of CFRP composites

Renowned for their high specific stiffness and exceptional structural integrity, carbon fibre reinforced polymer (CFRP)hasbecome indispensable in advanced aerospace and automotive engineering. However, the machining of these composites presents significant difficulties due to their abrasive constituents and anisotropic architecture. During milling, common problems such as rapid tool degradation, delamination of fibres, matrix debonding, and compromised surface finish are frequently observed. This study investigates the extent of tool deterioration and associated surface impairments during the dry milling of CFRP using an uncoated 8 mm tungsten carbide end mill. A selection of cutting parameters which is cutting speeds (100, 150, and 200 m/min) and feed rates (450, 600, and 850 mm/min) were examinedduring milling of CFRP.The results reveal that cutting speed predominantly affects tool degradation, accounting for a 62.1% increase in wear, while feed rate contributed to 42.7% of the variation. Microscopic analysis of the machined surfaces highlighted defects such as fibrerupture, resin smearing, interlaminar separation, and cracking-phenomena intensified by elevated thermal loading at higher cutting speeds. Based on the outcomes, employing moderate feed rates and lower cutting velocities is recommended to enhance surface integrity and prolong tool usability under dry machining conditions