Study On Micro-EDM Technology Of Particle Reinforced Aluminum Matrix Composite

As a relatively low cost metal matrix composite,particle reinforced aluminum matrix composite(SiCp/A1)has great application potential in aerospace,electronic instruments,communication equipment and other industries.The material has high hardness,high strength,high specific rigidity,high modulus of elasticity,good wear resistance,low density and good thermal conductivity.However,high hardness and high strength also restrict the processing and manufacturing of SiCp/Al composites,especially in the field of micro machining.The traditional machining methods will produce severe tool wear in the process of processing Si Cp/Al composites,which makes the machining accuracy and surface quality of SiCp/Al difficult to guarantee.Compared with the traditional machining methods,Micro-EDM has no macro cutting force in the process of machining,and has no requirements for the hardness and strength of the materials to be machined.It can process many high hardness materials and micro structures that are difficult to be machined by the traditional machining methods.It has incomparable advantages in many manufacturing fields.In this paper,the machining characteristics of micro EDM for SiCp/Al composites are studied.Through the observation and analysis of the surface morphology and element composition after machining,the influence of the characteristics of SiCp/Al composite and the energy intensity of micro EDM on the micro EDM of SiCp/Al composite is studied,and the erosion characteristics of the micro EDM of SiCp/Al composite are obtained.At the same time,the conclusion is verified and supplemented by collecting the electrical erosion debris produced after processing.At last,the erosion model of micro EDM for SiCp/Al composite was established.In order to further improve the discharge state of Micro-EDM of SiCp/Al composite,the influences of voltage,current,pulse width and non electric parameters such as liquid flushing and rotating speed on the machining time,electrode loss and pore size morphology were studied through the experiments of Micro-EDM in different depths.The results show that the process parameters should be combined according to their influence law,so that the three process parameters are relatively optimal;Too large or too small process parameters are not conducive to the processing performance of micro holes.In the process of Micro-EDM,chip removal has a great influence on the processing speed and processing stability in the process of deep micro hole processing.In this paper,the deep micro hole machining of Spiral,Groove(three grooves)and Edge cutting electrode with three special-shaped structures is compared with that of Cylindrical electrodes.Firstly,the flow state of working fluid between the four electrodes is analyzed by CFD simulation.According to the simulation results,the flow state in the hole of three special-shaped electrodes is better than that of cylindrical electrodes.The axial velocity of the working fluid in the deep micro hole processed by the Spiral-electrode is the largest,and the Archimedes spiral is formed in the processing,which can better discharge the erosion debris at the bottom of the hole diameter out of the hole.Secondly,the deep and micro hole experiments of four kinds of electrodes are carried out.The experimental results are consistent with the simulation results.The processing speed and the maximum processing depth of the three kinds of special-shaped electrodes are higher than that of the cylindrical electrodes.In general,among the four kinds of electrodes,the Spiral-electrode can effectively improve the processing performance of deep micropores.