Study On Processing Characteristics Of CFRP Based On Deionized Water Mixed With Carbon Nanotubes Using EDM

Carbon fiber reinforced plastic(CFRP)has been widely used in aerospace and other fields due to its excellent overall properties such as lightweight and high strength,high temperature resistance,corrosion resistance,excellent thermodynamic properties.However,when machining CFRP using conventional EDM,fraying carbon fibers easily causes intense spark discharge and short-circuiting,which make the spindle electrode head retract and then affect material removal rate(MRR),moreover,Joule heating from short-circuiting vaporizes insulating resin and affects surface characteristics.In order to improve the problems during machining CFRP using conventional EDM,the article has firstly conducted experimental studies on the mechanism of CFRP discharge erosion,secondly applied powder mixed EDM(PMEDM)in machining CFRP based on the principle that discharge gap increases by mixing powder,and then conducted series studies on processing characteristics of CFRP based on deionized water mixed with carbon nanotubes(CNT)using PMEDM.The EDM experimental platforms of CFRP have been set up,including single pulse discharge experimental platform and continuous discharge machining experimental platform.Firstly,experimental studies on the mechanism of CFRP discharge erosion are conducted,the high-speed camera is used to observe the discharge process of CFRP and 304 stainless steel under single-pulse discharge conditions.Experiments on CFRP discharge trace size under single-pulse discharge conditions and machining CFRP under continuous discharge conditions are conducted.Based on experiments above,the mechanism of CFRP discharge erosion is proposed and verified.Secondly,based on the mechanism of CFRP discharge erosion,the deionized water is selected as the base fluid to conduct basic experiments on CFRP using PMEDM.In order to explore the discharge characteristics of CFRP based on deionized water mixed with CNT using EDM,related experimental studies are conducted.Influencing factors of multiple discharge characteristics are clarified by pulsed power comparison,working medium comparison,and workpiece material comparison experiments.Moreover,further experiments are conducted to study and analyze effect of pulse voltage amplitude,pulse frequency,capacitance,loop resistance,and carbon nanotube powder concentration on multiple discharge characteristics.In order to explore the processing characteristics of CFRP based on deionized water mixed with CNT using EDM,related experimental studies are conducted.Effect of pulse voltage amplitude,pulse frequency,capacitance,loop resistance,carbon nanotube powder concentration and servo reference voltage on material removal rate(MRR),electrode wear rate(EWR)and surface quality are studied and analyzed.Higher MRR,lower EWR and better surface quality of hole are achieved under preferred processing parameters.