Carbon fiber, carbon fiber reinforced plastic (CFRP) and other composite materials used in aerospace, automotive, wind turbine components and other uses, are increasingly be used by designers. Their strong, light and thermally stable qualities are easy to appreciate. These qualities sometimes cause machinists to struggle with milling and drilling processes.
Cutting tool life can be very low due to the fact that these composites are highly abrasive. The low-thermal-conductivity materials have a problem with heat while machining. They do not produce a chip of any decent size, thus not allowing the chips to carry away heat from the machining process. Therefore, using the incorrect tool or even a dull one can cause the resin in the material to burn or melt. In addition, composites are constructed using layers of material held together by resin; they are disposed to splintering and delamination as they are machined.
Cutting Tools Chicago aka General Cutting Tools with Onsrud offers six flute cutting tools purposely designed with specific geometries and coatings for composites to overcome their machining challenges. Their compression cutters have intersecting up cut and down cut spiral flutes push the layers of the composite material together during machining to prevent delamination. Also, the resin is prevented from burning due to the high positive rake angles, delivering sharp, clean cuts. Diamond coating over the tool adds significant wear resistance caused by highly abrasive composites.