18 TH INTERNATIONAL CONFERENCE ON COMPOSITE MATERIALS 1. Introduction Aeronautic composites are inhomogeneous and most often consist of two distinctly phases. The reinforcement fibers are relatively hard and brittle whereas the matrix is soft and ductile. The anisotropy causes some severe challenges when machining composites. people in the field often experience a trade off between two main problems; on one hand, keeping the composite parts integrity and quality, and on the other hand, reducing the wear of the cutting tools. The high quality level required in aeronautic applications imposes a high quality cut of machined parts. Common defects that may occur during machining of these materials are delamination, over heat of the resin, uncut fibres, and pullout of the fibres. Delamination is when two or more layers are detached from each other, and may occur for example during drilling, when the drill exits the material. Overheating the resin may result in that the overall characteristics of the material is affected. Uncut fibres and fibre pullout may weaken the structure and cause unwanted wear on other structural parts. In order to partly avoid theses defects, our study is focused on the understanding of the cutting mechanism. As a first approach, the cutting forces are recorded during the cutting operation. The understanding of the cutting mechanism have been introduced by Koplev followed by M.Ramulu, Wang & Arola [2] .They were first to report the cutting process in Carbon/epoxy composite during orthogonal cutting operation and classify the chip formation in five types depending on the carbon ply orientation. J.Y.S Ahmad [5] discussed about cutting forces in trimming operation. All theses authors conclude that the orientation of fibers is a relevant factor for explaining the cutting edge failure and the material defects. Our study extends the cutting forces analysis to a high feed geometry tool. The most important part of the research is performed in CEROC (Researches and studies center on cutting tools technology), which is a jointly center between the company SAFETY, which provides cutting tool solutions, and the Laboratory of Mechanics and Rheology of the University of Tours (France). 2. Materials and experimental procedure: The tests have been performed using a milling machine PCI METEOR 10 (horizontal spindle, Nmax=24000tr/min, P=40kW) equipped with a Kistler dynamometer (Type 9255B). The figure 1 shows the placement of the part during the test. A multi-axial carbon/epoxy composite (T800S/M21) was tested. The orientation of the plies is the following [45/90/135/0] s .The ply thickness was 0.26mm. For each test, the cutting conditions were kept constant, as described in table 1. Cutting speed (m/min) 100 Fz (mm/tr/th) 0.3 Depht of cut (mm) 0.26 Radial engagement (mm) 35.6 Diameter (mm) 35.6 Lubrificant dry Table.1. Cutting conditions CARBON FIBER REINFORCED PLASTICS MACHINING: SURFACING STRATEGY FOR REDUCING CUTTING FORCES. A.Morandeau 1* , J.Bohlmark 2 , R.Leroy 1 , D.Bonhoure 3 , H.Chibane 1 , A.Bouchou 1 1 CEROC, Mechanics & Rheology Laboratory, François-Rabelais University, Tours, France 2 Sandvik Tooling Sverige AB, Stockholm, Sweden, 3 Safety S.A.S, 37230 Fondettes, France. * Corresponding author (antoine.morandeau@safety-cuttingtools.com) Keywords: Machining strategy, cutting forces, composite materials.