博士论文摘要常见错误解析.doc

Abstract1 Electrochemical machining (ECM 电化学加工) is an anodic dissolution process（阳极溶解工艺） of workpiece（to machine workpieces） in a flowing electrolyte（电解质） where the shape of the tool as cathode is copied into the workpiece as anode with the removal of the anode ion by ion（the shape of the cathode （as tool） is copied onto the workpiece (as anode) with the removal of the anode in ions ）. Due to the tiny size of metal ions, this micro-dissolution process brings ECM tremendous potential in the micro-manufacturing field. Wire electrical discharge machining (WEDM 线切割)（As for Wire electrical discharge machining (WEDM)），because of tool wear, the metal wire with the diameter of more than 30m must be used as the wire electrode of WEDM , and the wire must move quickly for the compensation of the tool wear（工具磨损补偿）. Therefore, WEDM will be restricted in the potential of micro machining in the future.( Therefore, WEDM has great limitations for its applications in micro machining in the future.)Wire electrochemical micromachining (WEMM 微细电化学线切割加工), which is the combination of electrochemical micro machining and the idea of wire cutting, was proposed as a new method of micro machining in this dissertation. Because of no electrode wear in this process， the micrometer or tens micrometer structure can be fabricated. The proposed technology can be used in the field of aviation, precise instrument, biological and medicinal instrument. The dissertation consisted of five sections, includingL( The proposed technique can be used in the field of aviation & aerospace industry, precision instrument(注意：精密仪器不能译为precise instrument), biological and medical(不能用medicinal) instrument. The dissertation consists(不要用过去时) of five sections, includingJ1. The fundamental theory of WEMM was investigated. Firstly, the characteristics of WEMM were summarized. Secondly, the theoretical model of WEMM was built based on the Bulter-Volmer equation and Faradays laws, and the top limit of the velocity of feed forward (feed rate 进给率) was studied.2. At last, the boundary layer theory of micro fluid (微流体边界层理论）was introduced into the analysis of the transport mechanism of materials in the micro scale gap（微尺度间隙） of WEMM, and the solution of improving the examination of materials in micro gap.( the solution to improving the discharge of materials from the micro gap, solution 固定搭配跟to,排放是discharge 而不是examination)3. The machining system of WEMM was developed. The movement system, measuring system, wire electrode system, high-frequency short-pulse power supply （高频短脉冲电源）and electrolyte system was designed. The two types of short-circuit: clogging short-circuit and unavoidable short-circuit was proposed, and the type of short-circuit can be discovered by the locality distributing of short-circuit,( the type ofcan be judged(determined) by the locality distribution(类型只能被判断，决定，不能被发现)。另外，该段中好几个was 应该是were, 因为主语都是复数) then the state of the micro gap in WEMM was on-line measured and distinguished. The method of punitive (penalty) function(罚函数) was used to optimize the velocity of feed forward(feed rate), and the strategy of servo-control system was designed. Finally, the control system was constructed using devices of virtual instruments(虚拟仪器), and the software of the system was designed based on Labwindows/CVL. 4. The new method of the online fabrication of the micrometer scale wire electrode used in WEMM was investigated. A model about the process of electrochemical etching（电化学刻蚀） was developed, the diameter of wire electrode was real-time monitored by precisely measuring the variation in resistance of the electrode. Based on electric field analysis, the device of electrochemical etching was designed to ensure the uniform(wear) of the wire electrode, and a monitoring system used for fabricating the wire electrode was developed base on virtual instrument technology. The online fabrication of wire electrode and the following process of WEMM were integrated into one system. Because of the compatibility of the technology, the machining precision (加工精度不能用precision, precision 专指仪器，系统，装置的精度)can be improved. Finally, a tungsten wire electrode of 5m in diameter was experimentally fabricated.5. The laws（rules） of machining process were experimentally investigated. The effects of various parameters on the machining accuracy, stability and surface quality were analyzed, and the impacts of velocity of feed(feed rate), frequency of feed (feed frequency), electrical parameters, electrolyte and the diameter of wire electrode on the machining process were experimentally investigated. Besides, the slight vibration of workpiece took place along the direction of the wire electrode length for effectively refreshing electrolyte in the machining area it was experimentally proved hat the slight vibration for improving the stability of WEMM was feasible. a slight vibration of workpiece taking place along the length direction of the wire electrode for effectively refreshing(更新) the electrolyte was experimentally proved to be able to improve the stability of WEMM6. the micro metal structures were obtained . Two models of machining process: cutting slits and fabricating structure were proposed. In model of cutting slits, parameter curve was divided into micro line segments, the wire electrode fed forward following the profile at constant speed, and the various micro grooves in width of 15nm and aspect-ratio of 10 were obtained; in model of fabrication fabricating structures , the profile was deviated from the same distance ,