Research On Simulation Of Material Ejection Process For SiC_p/Al Composites In EDM

SiC_p/Al composites fully combines the material advantages of SiC particles and aluminum,so that the properties of the single metal material are strengthened and have good mechanical properties.However,due to the high strength and high hardness of the material,it is difficult for the conventional processing method to meet the processing requirements green and efficient.As a non-traditional machining method,EDM is regarded as an effective method for machining SiC_p/Al composites without limitation of material properties.But,EDM technology also has problems such as unclear ejection mechanism,which hinders the further application of EDM to a certain extent.In this paper,the simulation analysis of the ejection process and the EDM test are carried out,and the test results and simulation results are verified.The role of the ejection force in the material ejection process of EDM is explored,which plays an important role in improving the material ejection efficiency of EDM.(1)Study on material ejection process under thermal explosion force.Based on the generation mode of thermal explosion force,the model of thermal explosion force acting was established.The motion state of molten material was analyzed,and the velocity field and particle motion process in the process of ejection were studied.The influence of thermal explosion force at different depths on the material ejection process is studied,and the influence of thermal explosion force at different depths on the maximum velocity and particle motion in the process of ejection is analyzed.(2)Study on material ejection process under thermal explosion force and steam torch force.Because there is more than one kind of ejecting force involved in EDM,the material ejecting model under the combined action of thermal explosion force and steam torch force is established to explore the influence of the combined action of the two ejecting forces on the material ejecting process.The motion state of molten materials and reinforced particles under the action of the two ejecting forces is analyzed,and the velocity field is studied and compared with that under the action of single ejecting force.At the same time,the influence of open circuit voltage and pulse current on the ejecting process and velocity field of molten materials and reinforced particles is analyzed,and the variation law of velocity field under different discharge parameters is obtained.(3)Test verification.The single pulse EDM test of SiC_p/Al composites was carried out.The morphology and size of the crater obtained under different discharge parameters were analyzed and compared with the simulation results.At the same time,the debris were collected and analyzed.The properties of the debris were analyzed and the shape of the debris was compared with the simulation results.It is verified that the simulation and test results have the same morphological characteristics,and debris contains reinforced particles,which proves that the reinforced particles are wrapped and ejected out by the molten matrix material.The work of this paper has certain reference significance for analyzing the research on the material ejection process of SiC_p/Al composites EDM and the influence of discharge parameters on the ejection process.