Study On The Side Gap Of Micro Holes In Electrochemical Machining

The rapid development of industrial technology has driven the progress of the entire advanced manufacturing industry,making MEMS products more and more important.The advantages of small size,light weight,and high accuracy of micro parts have been recognized by more and more people,and have been widely used in aerospace,medical machinery,and weaponry.A newly emerging processing method of electrochemical machining technology has unique application prospects because of its advantages of no processing force,high surface quality,and no loss of electrodes.As one of the core structures on turbine blades of aero-engines,the micro-holes require extremely harsh conditions.The surface quality of workpieces,the absence of remelted layers,and the presence of unprocessed internal forces are all required criteria.Due to the presence of stray corrosion in the electrochemical machining,the machining accuracy of the workpiece is reduced and the localization is poor.Although there are some ways to improve such as sidewall insulation,these methods require expensive equipment and are not suitable for mass production.In this paper,based on the electrochemical machining technology,the existence of micro-hole taper caused by stray corrosion in the process of micro-electrolysis processing micro-holes is studied.This paper first analyzes the influence of processing parameters on the side gap of micro hole.According to different processing voltage,pulse width,pulse period and feed rate,18 groups of comparative experiments are designed.With the increase of the processing voltage,pulse width,pulse period and the decrease of the feed rate,the entrance of the microholes increase,but there is a taper due to stray corrosion holes.When the planetary movement is applied to electrode,the taper is reduced.To understand the mechanism,a model is established to analyze the relationship between the side gap of micro hole in micro ECM and planetary movement of electrode.The experimental results show that the inlet diameter and the diameter difference between inlet and exit have significantly been reduced when the planetary movement of electrode is applied.When the micro hole depth is drilled to 200?m and the eccentric radius is set to 7?m,the diameter difference between inlet and exit with the planetary movement has been reduced 60% than that without planetary movement of electrode.When the micro hole depth is drilled to 300?m and the eccentric radius is set to 7?m,the diameter difference between inlet and exit with the planetary movement has been reduced 40% than that without planetary movement of electrode.