Research On Machining Thick Stainless Steel By Wire Electrochemical Micromachining

Wire Electrochemical Machining(Wire ECM)is a ECM process which uses a wire as the cathode to cut the workpiece.This method not only inherits the advantages of ECM,but also has its own characteristics.Insteading of manufacturing the complex shaping electrode in traditional ECM,the Wire ECM uses a thin wire as the electrode which moves along a 2D trajectory.Complex micro-structures and high-apect-ratio structures can be easily fabricated by the proposed Wire ECM.The technology offers unique advantages such as short leading time and low cost. In this paper,machining stainless steel with thickness of 5mm~20mm by Wire ECM was studied.Focusing on how to improve the electrolyte circulation in machining gap,the following tasks were undertook:(1)Electrolyte flowing along the wire electrode and wire winding were proposed to speedup the electrolyte refresh in machining gap.Assembly wire electrode fixture was designed,in which electrolyte flows along the wire electrode,in order to rinse machining gap smoothly.A wire winding setup was designed in which copper coil with jointless connector was used to accelerate reaction products removal.(2)An experimental system of Wire ECM has been structured,including motion platform and control system,wire electrode system,electrolyte circulation system,tool setting system and online detection system.(3)In order to analyse the influence of process parameters,a series of experiments were carried out.Effects of several process factors,such as machining voltage,feed speed,concentration of electrolyte and flow speed of electrolyte on machining accuracy and stability were investigated . Finally , by using optimization parameters , a series of micro grooves with 160-micrometer width in 5mm-thick stainless steel were obtained and the aspect ratio achieved nearly 30.(4)Machining experiments of the wire winding were carried out.At first,5mm-thick stainless steel was machined and the width of the groove was uniform,with no taper and machining process was stable.In order to verify whether or not more thicker stainless steel could be machined by this new method,experiments were carried out and 10mm-thick,even 20mm-thick stainless steel were manufactured successfully.The aspect ratio of the grooves in the 20mm-thick stainless steel was nearly 70.The result showed feed speed did not need to slow down while the thickness of stainless steel increased.