Study of milling of low thickness thermoplastic carbon fiber composites in function of tool geometry and cutting conditions

The application of carbon fiber reinforced thermoplastic matrix composites (CFRTP) is constantly increasing in various industrial sectors due to their mechanical properties and advantages compared to thermoset matrix composite. Nevertheless, CFRTP machining generates a current problem due to the anisotropy of these materials, the difficulty of impregnation of the reinforcement in the matrix, and its low melting temperature. For this reason, the study of conventional operations such as milling to achieve geometries with a good surface quality and reduced cosmetic defects is a line of research of great interest. In this article, a comparison of five cutting tools with different geometries has been made in CFRTP milling. The surface quality and the formation of visual defects such as fiber pull-out have been evaluated for each tool and combination of cutting parameters. In this sense, 16.42 mu m in terms of Rz is the minimum average value for the complete experiment obtained for a conventional tool (tool A). However, surface qualities in terms of Rz close to 20 mu m and minimum cosmetic defects have been obtained with a hybrid tool (tool C) with -10 degrees helix angle and 8 teeth with a combination of cutting parameters of 0.07 mm/tooth and 3000 rpm, being the most complete tool of the experiment.