Experimental Study On Optimization Of Process Parameters Of Low Speed Wire Electrical Discharge Machining

WEDM by instantaneous high-temperature pulse eroded material erosion.No macro-cutting force,easy to achieve high-hardness materials,sophisticated,complex processing,machinery manufacturing has become an indispensable means of processing.Titanium alloy TC4 which has the advantages of light weight,high strength,strong corrosion resistance and good thermal stability.But its thermal conductivity is small,low elastic modulus is a typical difficult to process materials.Mono crystalline silicon as micro electronic components in the system is widely used as a structural material,multi-application and semiconductor devices,solar cells and so on.Mono crystalline silicon is a brittle material,fracture toughness is low,mechanical processing is easy to produce tangential fracture or the overall fracture,the traditional processing method is difficult to process and processing of molding is difficult to great extent.The study of mono crystalline silicon and titanium alloy low-speed wire EDM cutting technology to promote the EDM technology in micro electromechanical systems and aerospace applications in the field of great significance.The discharge process of EDM is divided into four stages:the formation of discharge channel,the discharge energy conversion,the discharge of electro-erosive substance,the inter-electrode dielectric cooling process.Secondly,mono crystalline silicon and titanium alloy were used as the materials to carry out the low speed single wire cutting test.The peak current,open circuit voltage,pulse width,wire speed and wire tension were selected as the parameters.The surface roughness,the width of the slit and the material corrosion rate were taken as indexes.The single-factor test and the orthogonal experiment were designed to get the influence of the process parameters on the process parameters and the interaction between the parameters.Low speed wire cutting machine tools on the conventional materials such as steel,copper and other cutting technology has a mature multi-database.However,for titanium and mono crystalline silicon materials,the existing domestic and foreign electrical processing machine tools does not provide a reference database,so in this paper,a single cutting process based on the law,the titanium alloy and single crystal silicon processing is divided into rough cutting,semi-intensive and intensive.The optimization of multi objective parameters at different stages of multi cutting is carried out by using genetic algorithm and PSO algorithm,and the efficiency and surface quality of the multi objective are optimized.In addition,the surface and subsurface quality of titanium and mono crystalline silicon for low speed wire EDM processes include the thickness and continuity of the surface metamorphic layer,the heat affected layer,and the surface microstructure including cracks,pits,droplets and micro pores.Finally,the process characteristics of complex surface machining with low speed wire electrical discharge machining are studied,and the typical complex parts such as equal taper,variable taper,upper and lower contours are designed and tested,the machined surfaces were observed and the surface roughness was measured by surface profiler.