Experimental study on milling performance of 2D C/SiC composites using polycrystalline diamond tools

Abstract

The present paper concerns assessment of the milling machinability of 2D C/SiC composites using polycrystalline diamond (PCD) tools. Influences of milling parameters on cutting forces, surface integrity and machined defects were studied. Experimental results showed that cutting forces varied greatly in a milling circle due to the sudden changes of fiber cutting angle. As cutting speed increased, cutting forces and surface roughness decreased. Cutting forces and surface roughness both increased as feed rate increased. Fiber fracture, matrix damage and fiber-matrix debonding were three main material removal mechanisms during slot milling. Pits and cracks were main machined defects at ground surface, and they more easily happened at the intersection of woven yarns. Surface integrity of 90° fiber orientation was better than that of 0° fiber orientation. Machined defects of side edges had three types: fiber protrusion combined with surface damage, fiber protrusion and surface damage. Quantity and size of surface damage were much larger than fiber protrusion. Both of surface damage and fiber protrusion increased with the increase in feed rate. Higher cutting speeds could decrease the fiber protrusion of side edges evidently, however have minor influence on the surface damage.