The Effects of Milling and Drilling Process Parameters and Different Tool Path Strategies on the Quality of the CFRP Composites

Carbon fiber reinforced plastic (CFRP) composites are being used at a greater scale which is increasing the demands on automated production to improve productivity. These types of materials can be stronger than steel, about 40% lighter than aluminium, up to 80% lighter than steel and as stiff as titanium. Composite materials represent a good alternative to engineering materials, providing several important advantages in comparison to conventional materials, such as: light weight, mechanical and chemical resistance, low maintenance costs, high specific strength, higher stiffness and temperature stability, allowance of free forms modelling and specific design. Surface roughness evaluation is very important for many fundamental problems such as friction, contact deformation, heat and electric current conduction, tightness of contact joints and positional accuracy. For this reason, surface roughness, has been the subject of experimental and theoretical investigations for many decades. Also, surface roughness imposes one of the most critical constrains for the selection of machines and cutting parameters in process planning. In order to economically machine these materials with high part qualities, improvements in machining strategies must be made. This chapter presents the researches regarding different milling and drilling strategies in order to determine the best quality of the finished product. Flatness, parallelism, cylindricity, roughness and dimensional tolerances were measured using 3D CMM and the results were analysed using the Design Expert software.