Research On Electrochemical Cutting Using Micro/Sub-micro Tool Electrode

Micro electrochemical cutting is a promising technology for manufacturing micro metal structures and parts.In micro electrochemical cutting,an electrode is employed as the cathode and the workpiece as the anode.As the electrode moves towards the workpiece,material is electrochemically removed from the latter,with the creation of micro features.The introduction of ultrashort pulse power supply has greatly improved the machining accuracy of micro electrochemical cutting.The tool electrode is the vital part of micro electrochemical cutting because both the machining precision and the minimum scale of the processed micro features achievable depend mainly on the size of the tool electrode.Electrochemical etching is one of the preparing methods of tool electrodes.Compared with other electrode preparation methods,electrochemical etching has advantages in easy operating,good processing surface quality and high machining efficiency.In this dissertation,research on fabricating micro/sub-micro wire electrodes by electrochemical etching has been conducted,and experiments of micro electrochemical cutting using fabricated tool electrodes have been made and investigated.The main contributions are as follows:A new method for in situ fabrication of a micro wire electrode using dynamic liquid membrane etching has been presented.To improve the controllability of the size of the micro wire electrode,a mathematical model of dynamic liquid membrane etching has been constructed.Experimental results are in good agreement with results generated from the model.Using the proposed method,micro wire electrodes with the diameter of 14?m have been produced,and micro slits with the width of 34?m have been electrochemically machined using the micro wire electrode fabricated in situ.The fabricating method of triple-stepped cylindrical tool electrodes using electrochemical etching has been proposed.Triple-stepped cylindrical tool electrodes with different diameters of the lower end have been produced using the optimal process parameters of electrochemical etching.Based on the fabricated electrodes,sets of experiments are carried out to study the effect of the thickness of the workpiece on micro electrochemical cutting.The fabricating method of tip tool electrode using liquid membrane electrochemical etching aided by straight reciprocating motion has been proposed.Tip tool electrodes with average diameter of 400 nm have been obtained using the optimal process parameters.Experiments of micro electrochemical cutting using tip tool electrode have been conducted.By decreasing pulse width,the minimum scale of the processed micro slits achievable has been found.Taking tip tool electrodes and triple-stepped cylindrical tool electrodes,sets of experiments are carried out to study the effect of the diameter of the tool electrode on micro electrochemical cutting.