Study on tool wear and cutting performance of CFRP for inclined angle milling

Carbon fiber reinforced plastic (CFRP) has been widely used in aviation, aerospace, automotive, and other fields due to its advantages of high specific strength and high specific modulus. However, as a typical anisotropic material, CFRP has a more prominent problem in processing, that is, tool wear, which is easy to form machining defects such as burrs, tearing, and delamination. In this paper, the comparative experimental study on inclined angle milling and spiral milling of CFRP was carried out. The milling axial force, tool wear, quality of hole entrance and exit, and micro-morphology of the hole wall under the two milling methods were analyzed. The results show that compared with spiral milling, the axial force of inclined angle milling is relatively small, and the fluctuation is relatively smooth. The wear of inclined angle milling tool end edge is mainly concentrated in the connection area of end and side edges (CAES), and the wear of side edge is mainly concentrated in the tip of rhombic tooth, while the wear of spiral milling tool end edge and side edge is relatively uniform. As the number of holes increases, the wear morphology of inclined angle milling end edge changes from a small area of discontinuous crescent shape to a large area of continuous triangular, while the wear morphology of spiral milling end edge changes from a long strip to a large area of parallelogram. With the increase of tool wear, the holes by inclined angle milling produce fewer burrs and tearing, there are some defects such as fiber fracture residues and cavities on the surface of the hole wall, while the surface of the hole wall by spiral milling shows a large amount of chip adhesion and pit.