Edge Trimming of CFRP Composites with Diamond Coated Tools: Edge Wear and Surface Characteristics

The work presented here illustrates the wear behavior of CVD diamond coated carbide tools during the machining of carbon fiber-reinforced composites. Cutting experiments were conducted on a CNC milling machine for edge trimming of a 9-mm thick multi-layered carbon fiber-reinforced epoxy laminate in a climb cutting configuration. The effects of feed speed and diamond film thickness on the wear behavior of the coated tools were determined. In addition, characteristics of the worn cutting edge were studied using optical and scanning electron microscopes. It was shown that diamond coated tools generally performed better than the uncoated tools under all conditions. Uniform wear by abrasion of the diamond film, without exposing the substrate, was obtained when cutting at low feed speeds with thicker coatings. At higher feed speeds the wear of the coated tools was characterized by abrasion through the diamond film and exposure and wear of the substrate. Surface roughness obtained with diamond coated tools was comparable to or lower than that of uncoated tools.