Basic Research On Technology Of Combined Micro-machining Of USM And ECM

This dissertation summarizes the recent applied state of micro-manufacturing technologies, introduces the basic principle, specialty and application of micro-USM (Ultrasonic Machining) and micro-ECM (Electrochemical Machining), analyzes their problems and research future. The machining mechanism, particularity of PECM (Pulse Electrochemical Machining) and Ultrasonic vibration combined ECM are also introduced. The machining mechanism and technology advantages of combined micro-machining of UCM and ECM is dissertated.The test system scheme of combined micro-machining of UCM and ECM is given, including micro-feed of worktable, the design and manufacturing techniques of the tool-cathode, the methods to provide working-liquid, the detection of micro-displacement and working process parameters, the measurement of machining precision.The machining tool applied in micro-machining field is very small; its request of accuracy is very high, so the design and manufacture of micro-tool-cathode is one of the key technology and difficulty in combined micro-machining of UCM and ECM. In this paper many different shapes of tool-cathode are designed. The manufacture technical methods of micro-tool-cathode are studied and perfected, such as WEDM (Wire Electric Discharge Machining), combinative EDM etc. Several different micro-tools are successfully processed which are suitable for the requests of combined micro-machining of UCM and ECM.Many experiments are done by USM in different materials using micro-tools. Then compared tests by PECM, Ultrasonic vibration combined ECM, combined micro-machining of UCM and ECM in different materials are done. The feasibility, reliability and technology advantages of combined micro-machining of UCM and ECM are further validated. Then experiments are done aiming at researching the machining parameters of combined micro-machining of UCM and ECM, such as ECM parameters, Ultrasonic amplitude, frequency, feed pressure and the crocus granularity. Then Micro-gear part has been machined using optimized parameters.In the course of experiments several special phenomenon and problems are found. The settle methods are given in this paper. The later studies and applied future of this new micro-machining methods--combined micro-machining of UCM and ECM in the fields of accurate 3D (three-dimension) micro-structures of difficult-to-machine hard fragile metals are suggested.