Cutting performance and wear behavior of diamond, coated cemented carbide and PCBN tools during milling of Cf/SiC composites

As an advanced material, Cf/SiC composites are wildly used in many aerospace industries due to their excellent properties. However, machining the material often encounters many problems, such as poor machining quality, severe tool wear, and low processing efficiency. Tool materials have a significant influence on the cutting performance of tools and the surface quality of the workpiece being machined. In this study, milling experiments have been performed on Cf/SiC composites with different tools. The tool wear pattern, progression, mechanisms, and milling temperature were investigated. The machined surface quality and removal mechanisms of Cf/SiC composites were studied. The results indicated that polycrystalline diamond (PCD) tools have better cutting performance in milling Cf/SiC composites than other tools. Surface defects, milling temperature, and machined surface roughness (Sa = 2.9 μm) obtained by machining Cf/SiC composites using the PCD tool would be lower. The material removal mode is brittle fracture, and the surface damage (including fiber debonding, fiber pullout, and pits, etc.) is related to the direction of the fibers. Fibers in the X and Y directions can lead to more machined surface defects. Since hard particles formed in the machining process and protruding fibers constantly scratched the flank face, diamond grains were spalled off from PCD tools, resulting in abrasive wear.