High feed rate milling of carbon fiber reinforced plastic with PCD tool

Carbon fiber reinforced plastic (CFRP) has recently been applied to aircraft structures. In milling of CFRP, the surface finish is sometimes deteriorated by delamination of polymer with uncut fibers. Because the cutting of CFRP also appears anisotropy, the surface finish depends on the fiber cutting angle, which is the cutting direction for the fiber orientation. Furthermore, in the manufacturing of aircraft parts, high machining rates are required for large removal areas. This study investigates the surface finish and the tool wear in the milling of CFRP with a 10 mm diameter PCD end mill at high feed rates up to 3000 mm/min. Delamination-free and wavy profile-free surfaces are finished at a cutting speed of 314 m/min and a feed rate of 3000 mm/min using the end mills at rake angles of 5°, 10°, and 15°. Delamination suppression is associated with the indentation load applied to the workpiece surface in the engagement of cutting edge in up-cutting. Then, the tool wear is discussed in the milling of 16-layered CFRP. An approach based on an abrasive wear model is presented to identify the wear characteristics for the fiber cutting angles. In the wear test of this study, the wear rate increases up to a fiber cutting angle of 45°; decreases to 135° (−45°); and increases again to 180° (0°). The presented approach is effective in estimation of flank wear distribution associated with the radial depth of cut