Effect of Carbon Fiber Orientation and Helix Angle on CFRP Cutting Characteristics by End-Milling

摘要

Carbon Fiber Reinforced Plastics (CFRP) have outstanding lightweight material characteristics and tensile strength. The use of CFRP in aerospace industry has been successfully implemented and is expected to grow in the future. However, the mechanical properties of CFRP are affected by differences in the distribution and orientation of the carbon fibers and their adhesion to the binding material. CFRP shows intense anisotropy in strength of carbon fiber depending on its mechanical properties and the state of the carbon fiber orientation. Therefore, the tool life shortest and the surface finish quality of the material becomes unstable and eventually difficult to cut. This paper presents the effect on carbon fiber orientation and helix angle with CFRP cutting characteristics by end milling. Here, three types of orientations were machined by straight type end mills and constant cutting conditions with a cutting speed 70 m/min, a feed rate 0.056 mm/tooth and 3 mm depth of cut. Our results showed that the tool helix angle 0° gave a better surface finish than the other tools, irrespective of the fiber orientation. The helix angle is greatly affected by the exposure of the fibers from the surface. Axial force (F_z) is negligible quantity for helix angle 0°, and cutting force is low. The carbon fiber orientation of 45° and -45° has exfoliation-like dimples.