The influence of PCBN inserts microgeometry on cutting forces, surface roughness, and tool wear when milling Inconel 718

This study investigates the effect of cutting edge microgeometry on the milling of Inconel 718, a superalloy widely used in aircraft engine components. Face milling tests were conducted using a Ø63 mm tool with unevenly distributed polycrystalline cubic boron nitride (PCBN) inserts, comparing inserts with a chamfered cutting edge (15° × 0.2 mm) and sharp cutting edges. The experiments examined cutting forces, surface roughness (parameters Ra and Rz), and tool wear at various cutting speeds (80–300 m/min). The results revealed that sharp inserts generated lower cutting forces compared to chamfered inserts, with the axial force being the greatest component for chamfered tools and the lowest for sharp ones. The dominant tool wear mechanism for both insert types was chipping; however, sharp inserts also exhibited built–up edge formation and, in one case, a significantly deeper crater compared to chamfered inserts which showed smaller crater depths. The study concludes that the cutting edge microgeometry significantly influences the machining performance in terms of cutting forces, surface quality, and tool wear when milling Inconel 718.