Research On Grinding Of Carbon Fiber Reinforced Plastics Used For Aviation

An important direction of new materials is to develop new techniques of composition. Carbon fiber, which has a very outstanding performance, is one of reinforcing material in advanced composite materials. Carbon fiber reinforced plastics have been widely applied in artificial satellites, high-performance aircraft and so on as one material used in aviation and aerospace. However, because of its high brittleness and hardness, carbon fiber reinforced plastics belongs to difficult-to-cut materials, and when it is machined, problems such as delamination, tearing, tipping, burr and so on are easy to occur. So the focus and the difficulty of the present research is how to improve its machining performance. Cutting force is an important performance parameter in the cutting process, and its size will make a direct impact on cutting heat and cutting tool life and so on, which will consequently affect the manufacturing quality of workpiece and the dimensional accuracy of the work. Hence, study on the change rule of cutting force is of important guiding significance for the machining process.In this thesis, an intensive study on grinding and high-speed milling of carbon fiber reinforced plastics was presented. Experimental investigation method was used to research the influence of cutting parameters on grinding and milling forces, and then multiple linear regression analysis was carried on for experimental data of these forces by using software SPSS. At last, the empirical equations concerning these two forces and cutting speed, feed rate, cutting depth, etc. were created.Grinding experiment and high-speed milling experiment for carbon fiber reinforced plastics were respectively carried out in this thesis. Diamond grinding wheel bonded by ceramic and resin were separately employed in the grinding test, and grinding parameters such as grinding depth, circular linear speed of the grinding wheel and feed rate were studied. The orthogonal experimental design method with 3 factors and 3 levels,9 group tests in total, was designed for the grinding experiment. Diamond end milling cutter was used in high-speed milling test. The single factor experimental design method with 5 different spindle speeds (corresponding to 5 different cutting cutting speed of the miller cutter) and 3 different feeds per tooth,15 group tests in total, was adopted for the high-speed milling experiment mentioned above, and the milling parameters such as spindle speed. The strain-gage machine tool dynamometer and piezoelectric resistance dynamometer were used to measure cutting force and data collecting instrument was used for data acquisition in the experimental process. After the test, both of intuitive analysis and multiple linear regression analysis were applied to analyze the experimental data, and variation law of grinding and milling forces influenced by cutting parameters and experimental formula under special cutting conditions were obtained. Finally, empirical equations were demonstrated to fit the experimental datas well and were of good significance by relevant statistic tests, which can provide a better reference for the selection of optimal cutting parameters when grinding and milling carbon fiber reinforced plastics.