随着MEMS技术的发展，对于微型马达、微型传感器等微小零件的需求逐渐增多。微细电火花加工由于自身的非接触、与被加工材料硬度无关以及较好的可控性等特点，非常适合进行微小零件的加工。但是由于加工尺度小，放电爆炸力弱，在加工过程中放电屑难以从极间排出，使得放电稳定性降低，进而降低材料的去除效率并增加了电极的损耗，限制了微细电火花加工技术的应用范围。基于非接触给电的高主轴转速微细电火花加工技术，能够实现数万转每分钟以上的电极旋转速度，高的电极旋转速度能够改善极间放电状态，从而提高加工的材料去除率并降低加工过程中的电极损耗。这对于扩大微细电火花加工应用领域具有十分重要的意义。 在分析非接触给电微细电火花加工原理的基础上，本文首先进行了不考虑分布电容和分布电感下非接触给电微细电火花加工的理论建模分析，明确了该条件下非接触给电微细电火花加工的充／放电特性。考虑到微小放电能量下放电回路中分布电容和分布电感可能对放电产生影响，而后又进行了分布电容和分布电感影响下非接触给电微细电火花加工的理论建模分析，明确了分布电容和分布电感对非接触给电微细电火花加工充／放电特性的影响规律。 依据非接触给电微细电火花加工原理及充／放电特性，本文设计了高主轴转速非接触给电微细电火花加工系统，主要包括：高频脉冲方波电源、非接触给电及非接触检测装置、工具电极夹持装置、基于极间电压非接触检测的伺服控制系统等。通过对非接触检测等效电路的仿真分析，确定了检测电极的尺寸。基于该检测电压实现了非接触给电方式下微细电火花加工的伺服控制，同时避免了检测回路对放电的影响，最终实现了稳定的高主轴转速微细电火花加工。 为明确高主轴转速微细电火花加工过程中工具电极与工件之间高的相对线速度对电极损耗的影响规律，本文建立了移动热源下单脉冲电极侧面放电条件下的热分析模型，应用有限元法进行计算不同主轴转速下的电极表面瞬态温度场分布。仿真结果表明电极转速越大，电极表面线速度越大，输入到电极表面的热流密度越小，电极熔融区沿电极轴向和径向的尺寸就越小，沿电极表面线速度方向的尺寸越大；当电极表面线速度增大到20m／s时，电极上熔融区的温度小于电极材料的熔点，可以实现无电极损耗的加工。通过电极侧面放电铣削加工电极表面线速度对比实验研究结果，可知增大电极表面线速度能够实现更小的沿电极径向损耗，并且能够使加工后的电极表面粗糙度变得更小。沿电极径向损耗和加工后的电极表面粗糙度变小，能够说明放电凹坑的深度随着电极表面线速度的提高而变浅，与温度场仿真结果一致。为明确高主轴转速微细电火花微小孔加工过程中电极转速对排屑的影响，本文建立了微小孔加工极间间隙流场的模型，仿真分析了电极转速对极间间隙流场及问隙中放电屑颗粒的分布的影响。仿真结果表明，随着电极转速的提高，极间放电屑粒子更加容易从底部以及侧面间隙进入自由液面，即在微细电火花微小孔加工中，放电屑在主轴高速旋转时更易从极间排出。通过不同转速下微细电火花微小孔加工实验研究结果，可知提高主轴转速能够有效地提高加工速度并且降低极间短路发生的概率，间接地证明了提高电极转速能够促进排屑，与流场仿真结果一致。 为实现高主轴转速微细电极的加工，本文进行了块电极电火花磨削加工的研究，在主轴转速为60000r／min的情况下，加工出直径为5μm、长度为80μm，长径比为16的微细轴。为明确主轴转速对微小孔放电加工特性的影响规律，本文进行了不同主轴转速下的微小孔加工实验研究，分析了主轴转速对材料去除率、电极损耗、所加工的孔的锥度以及孔壁的表面粗糙度的影响，研究结果表明主轴转速越高，材料去除率越大，电极损耗越小，所加工小孔的锥度以及孔壁的表面粗糙度越小；同时，分析了不同电极直径、不同孔深下，主轴转速对材料去除率和电极损耗的影响，研究结果表明提高主轴转速对大电极直径和深孔加工时材料去除率的提高效果更好，对小电极直径和深孔加工时电极损耗降低效果更好。最后，通过削边电极和圆柱电极加工小孔的对比实验，进一步验证了电极高速旋转有利于放电屑从极间排出，从而提高放电状态稳定性。 为明确主轴转速对微细电火花铣削加工特性的影响，本文首先进行了高主轴转速电极底面放电铣削加工的实验研究，分析了主轴转速对电极损耗和加工表面粗糙度的影响，研究结果表明主轴转速的提高，有利于电极损耗和加工面的表面粗糙度的降低。而后，本文进行了高主轴转速下电极侧面放电铣削加工的实验研究，研究结果表明提高电极表面线速度有利于材料去除率的提高和电极损耗的降低，并能够获得更好的加工表面质量。 关键词：微细电火花加工；高主轴转速；非接触给电；非接触检测；材料去除率；电极损耗

 With the development of MEMS technology, the demand for micro-motors, micro-sensors and other small parts is increasing. Micro-EDM is very suitable for machining the small parts due to its non-contact, independent of the hardness of the material being processed and better controllability. However, due to the small machining scale and the weak discharge explosion force, the debris in the working gap often accumulate in the gap and cannot be flushed easily, which leads to unstable discharge state. As a result, the machining speed is reduced and the tool electrode wear is increased, which seriously limits the application range of micro -EDM technology. Based on non-contact electric feeding method, high spindle speed micro-EDM technology can realize electrode rotational speed of tens of thousands of revolutions per minute or more. High electrode rotational speed can effectively improve the discharge state, improving machining efficiency and reducing electrode wear. This is very important for expanding the practical application of micro-EDM and expanding its application fields. Based on the analysis of the principle of micro-EDM using non-contact electric feeding method, this dissertation firstly analyzes the theoretical modeling of micro-EDM using non-contact electric feeding method without considering distributed capacitance and distributed inductance, and clarifies the charging/discharging characteristics of micro-EDM using non-contact electric feeding method in that conditions. Considering the small discharge energy, the distributed capacitance and distributed inductance in the discharge circuit may affect the discharge, and then the theoretical modeling analysis of micro-EDM using non-contact electric feeding method under the influence of distributed capacitance and distributed inductance is carried out, and the influence law of distributed capacitance and distributed inductance on the charging/discharging characteristics of micro-EDM using non-contact electric feeding method is clarified. According to the principle and charging/discharging characteristics of micro-EDM using non-contact electric feeding method, this dissertation designed a machining system for micro-EDM using non-contact electric feeding method with high spindle speed, which mainly includes: high-frequency pulse power supply, non-contact electric feeding and non-contact measuring device, tool electrode holder device, and servo control system based on non-contact measuring. Through the simulation analysis of the non-contact measuring equivalent circuit, the size of the measuring electrode was determined. Based on the measuring voltage, the servo control of the micro EDM using non-contact electric feeding method is realized, and the influence of the measuring circuit on the discharge is avoided. And, finally a stable micro-EDM with high spindle speed can be achieved. In order to clarify the influence of the relative linear velocity of the tool electrode and the workpiece on the electrode wear in micro-EDM with high spindle speed, this dissertation established a thermal analysis model of single-pulse electrode side discharge under moving heat source, and conducted simulation analysis of electrode surface transient temperature field distribution under different spindle speed. The simulation results showed that the greater the electrode rotational speed, the greater the linear velocity of the electrode surface, the smaller the heat flux density input to the electrode surface, the smaller the electrode melting zone along the axial and radial dimensions of the electrode, the larger the size along the electrode surface linear velocity direction; When the linear velocity of the electrode surface is increased to 20 m/s, the temperature of the molten region on the electrode is lower than the melting point of the electrode material, and machining without electrode wear can be realized. Comparing the experimental results of the linear velocity of the electrode surface in electrode side discharge milling, it can be seen that increasing the electrode surface linear velocity can achieve smaller electrode wear, and can make the electrode surface roughness smaller. The radial wear along the electrode and the surface roughness of the electrode after machining become smaller, which can explain that the depth of the discharge crater becomes shallower as the linear velocity of the electrode surface increases. The experimental result is consistent with the temperature field simulation results. In order to clarify the effect of electrode rotational speed on flushing debris particles from the gap in the micro-EDM drilling with high spindle speed, this dissertation established a model of the working gap flow field in micro-EDM with side flushing and simulation analyzed the influence of the electrode rotating speed on the flow field and the distribution of the discharge debris particles in the gap. The simulation results showed that as the electrode rotational speed increases, the discharge particles are more likely to enter the free surface from the frontal and lateral gap. That is, in micro-hole machining, the discharge debris are more likely to flush from the gap during high-speed rotation of the spindle. Through the experimental results of micro-hole machining at different speeds, it can be seen that increasing the spindle speed can effectively improve the machining speed and reduce the probability of occurrence of short circuit, which indirectly proves that increasing the rotating speed can promote the removal of the discharge particles. And the experimental result is consistent with the flow field simulation results. In order to realize the micro electrode machining with high spindle speed, this dissertation carried out the research of block electrical discharge grinding (BEDG). In the case where the spindle rotation speed is 60000r/min, a micro rod of 5μm in diameter, 80μm in length and 16 in high aspect ratio is machined. In order to clarify the influence of spindle rotational speed on machining characteristics of micro-holes machining, this dissertation analyzed the effect of spindle rotational speed on the material removal rates, the electrode wear, the taper of the machined holes and the surface roughness of the hole wall, and the results showed that the higher the spindle rotational speed, the greater the material removal rate, the smaller the electrode wear, the smaller the taper of hole and the surface roughness of the hole wall. At the same time, it analyzed the effect of spindle rotational speed on the material removal rates and the electrode wear in different electrode diameters and different hole depth, and the results showed that increasing the spindle rotational speed has a better effect on increasing the material removal rate of the larger electrode diameters and deeper hole machining, and has a better effect on reducing electrode wear of smaller electrode diameters and deeper hole machining. Finally, it was further verified that the high electrode rotational speed was good for flushing the debris from the gap and improving the stability of the discharge state by the comparison experiment of machining the small holes using the edging electrode and the cylindrical electrode. In order to clarify the influence of the spindle rotational speed on machining characteristics in micro-EDM milling, this dissertation firstly studied high spindle speed micro-EDM milling using electrode end, analyzed the influence of the spindle rotational speed on the electrode wear and the machining surface roughness and the results showed that increasing the spindle rotational speed was good for reducing the electrode wear and the surface roughness of the machined surface. Then, it studied high spindle speed micro-EDM milling using electrode sidewall, analyzed the influence of the electrode surface linear velocity on the material removal rate, electrode wear and machining surface quality, and the results showed that increasing the linear velocity of the electrode surface was good for the improvement of the material removal rate, the reduction of the electrode wear, and obtaining a better surface quality. Keywords: micro-EDM, high spindle speed, non-contact electric feeding, non-contact measuring, material removal rate, electrode wear