Simulation And Experimental Study On Drilling High Volume Fraction SiCp/Al Composite

SiC particle reinforced aluminum matrix composites(SiCp/Al composites) is a metal matrix composite material having low density, high specific strength and specific stiffness, low thermal expansion coefficient, and other excellent physical and thermal properties. It is widely used in communication satellites, avionics and military radar and other fields. However, the high hardness and high wear resistance of this composite material leads to its serious tool wear and surface defects, which greatly limits the application of this material. The research for cutting SiCp/Al composites presented in current literature is not widespread, and for drilling of the material is less and less. Based on the above situation, exploring the cutting process and in-depth study of the mechanism of SiCp/Al composites is very necessary to promote SiCp/Al composites used in high-end technology is of great significance. Drilling simulation and experimental study aiming at high volume score(65%) and average particle sizes of 10μm of SiCp/Al composites for small diameter hole were studied in this thesis, the main contents are showed as follows:(1) The FEM of drilling process SiCp/Al6063/65 p composites. An acceptable model was developed by repeated calculation and optimization which can be used to simulate a three-dimensional FEM of the drilling any material. The material parameters of C45 were used in the simulations. Then appropriate experiments were carried out to verify the feasibility of the model. Based on this research progress, combined with the results of SHPB test, the equivalent homogeneous property SiCp/Al6063/65 p composites was used to simulate the drilling process. Its corresponding experiments were carried out to verify the feasibility of the model from chip deforming, morphology and cutting forces.(2) Orthogonal experiments were carried out to drill SiCp/Al6063/65 p composites using PCD drill, studying the influence of feed velocity, rotational speed and step depth on the drilling force. Experimental thrust force and torque variance analysis was carried out to estimate the significance of speed, feed rate, and step depth in drilling SiCp/Al6063/65 p composite process using PCD drill. The results were derived to develop empirical formula of the thrust force and torque. Additionally, the effects of factors on drilling forces were compared using PCD drill and carbide drill under the same parameters.(3) Single factor experiments of drilling SiCp/Al6063/65 p composite were carried out, combining Keyence laser microscopy and scanning electron microscopy to observe the machined hole surface, visual analysis of the formation mechanism. A comparison of hole surface topography, surface roughness and chip morphology using PCD drill and carbide drill was studied. The impact of rotational speed and feed velocity to the hole surface quality was analyzed.(4) Combined single factor experiments, the wear and tear of PCD drill and carbide drill were analyzed. To analyze the damage mechanism of diamond tools, a simplified model of the mechanical damage PCD cutting tool were established. In addition, the morphology of the entry and exit edge defects was studied, and also formation mechanism.