Research Of Experimental And Finite Element Simulation On Cutting Of SiC_p/Al Particle Reinforced Composites

SiC_p/Al particle reinforced composite has high specific modulus,high specific strength,low coefficient of thermal expansion,excellent fatigue and corrosion resistance,which has been widely used in aerospace,automotive,electronic and military fields.During the processing of SiC_p/Al particle reinforced composite,the existence of reinforced particles result to serious tool wear,surface defects.In order to improve the machining efficiency and quality,the cutting mechanism of SiC_p/Al composites is studied by means of finite element simulation and experiment.The main research contents and conclusions are as follows:(1)The experiment of SiC_p/Al composites was carried out.For SiC_p/Al composites with 45%particle content(particle size 5?m),orthogonal cutting and single factor experiments were carried out with five cutting speeds and five cutting depths on CA6140.It is found that the chip is a typical segmented chip.The relationship between cutting force and cutting speed is a cubic function.The relationship between cutting force and cutting denpth is a logarithmic function.The relationship between cutting temperature and cutting speed is logarithmic.The relationship between cutting temperature and cutting depth is a cubic.(2)A two-dimensional cutting simulation of SiC_p/Al particle reinforced composite was carried out.The interface models established by three methods are analyzed and compared.The results show that:The cohesive model with zero thickness can better show the strengthening effect of reinforcing particles on matrix materials and the cracking process of interface in cutting process.The simulation of single particle model shows that there are two forms of particle cracking,one is the direct contact between cutting edge and particle,the other is the indirect interaction between tool and particle.Through the second development of ABAQUS by writing Python script,the multi-particle simulation model was established.The validity of the model was verified by comparing simulation results of the chip shape,cutting force and cutting temperature with that of experiments.The influence of cutting parameters on cutting force and cutting temperature was analyzed.(3)A three-dimensional cutting simulation of SiC_p/Al particle reinforced composite was carried out.Based on a method of one sixth partition of the model,the finite element modeling and mesh generation of the three-dimensional model were realized.Comparing the single particle cutting model with the two-dimensional model,it is found that the cutting edge is located in the center of the particles,the fracture mode of the particles is cut off,and the maximum stress is concentrated in the contact position between the particles and the matrix.Through python programming,a three-dimensional model of multi-particle with cube and sphere shape was established.Comparing the three-dimensional model with the two-dimensional model,it is found that both of them can better predict the cutting force.The three-dimensional model is relatively inefficient in calculation,but it can more truly show the machined surface morphology and particle breakage.The influence of particle shape,particle size and volume fraction ratio on the cutting process is simulated by a multi particle three-dimensional model.