| SiCp/Al composite has been widely used because of its high specific strength,high specific steel,high thermal conductivity and other excellent properties.However,the high hardness and strength of SiCp/Al composite bring many disadvantages to the traditional machining methods.EDM is considered as one of the most effective methods for machining SiCp/Al composite because of its non-contact machining characteristics.This paper aims at the problems of the erosion characteristics of SiCp/Al composite in EDM are not clear enough,and the special process law is not mastered enough,carry out experimental study.The main research work is as follows:(1)Study on the erosion characteristics of SiCp/Al composite in EDM.The surface of SiCp/Al composite and aluminum alloy after single pulse machining was observed by SEM,and the relationship between surface morphology and material removal was analyzed.The melting corrosion characteristics of SiCp/Al composite were studied from the energy spectrum analysis of material surface.The comparative analysis of material removal rate and electrode wear between SiCp/Al composite and aluminum alloy was carried out,the etching products of SiCp/Al composite after EDM were collected,and the throwing characteristics of the composite were studied by the element analysis of the removal products.(2)Study on the influence factors of material removal rate,electrode loss and surface quality in EDM of SiCp/Al composite.In the aspect of material removal rate and electrode loss,the effects of machining polarity,electrode material,open circuit voltage,peak current and spindle speed on machining are analyzed,and the effects of the above factors on machining are analyzed from the aspect of composite material removal characteristics.In the aspect of surface quality research,the analysis is divided into two cases: surface morphology and surface roughness.Through the observation of machined surface morphology and the measurement of surface roughness,the formation of surface bulge,depression and recast Layer and the influence of process conditions on them are analyzed,and the influence of different process conditions on surface roughness is studied.(3)Study on the process optimization based on response surface method.Based on the single factor test results of SiCp/Al composite EDM,three representative factors and levels of open circuit voltage,peak current and spindle speed are selected.The box Behnken test method is used to design the machining test.According to the test results,the functions of open circuit voltage,peak current,spindle speed,material removal rate and electrode loss are established in the model,the response surface is fitted and evaluated,and the interaction between factors is analyzed.Aiming at the highest material removal rate and the lowest electrode wear,the optimization results are extracted in design expert 10 software and verified by experiments.The research work in this paper reveals the etching characteristics of SiCp/Al composites and the influence of processing conditions on the machining,which has important guiding significance for improving the machining ability of SiCp/Al composites. |
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