电镀电极丝电火花线切割及螺旋电极电火花小孔加工研究

发布时间：2018-01-10 20:19

本文关键词：电镀电极丝电火花线切割及螺旋电极电火花小孔加工研究　出处：《太原理工大学》2015年硕士论文　论文类型：学位论文

【摘要】：电火花加工因其独有的优势，在工业上具有着不可替代的作用,由于其加工特点，对电极的机械性能要求较低，这就使得对电极的各种处理成为可能。本文针对电火花加工的两个常见问题，提出改进电极的解决方案。电火花加工的两个常见问题是： (1)高速走丝线切割电极丝损耗较快、寿命较低。由电火花加工本质决定，在高速走丝线切割中电极丝的损耗不可避免，又因电极丝循环使用，所以它会随着加工而不断变细最终断裂，影响了高速走丝线切割的正常进行。本文提出电极丝补偿法，以降低电极丝损耗，最终达到提高电极丝寿命的目的。文中主要通过电镀方法来补偿电极丝损耗，分析了电镀对电极丝的影响并设计电镀过程。选Cu为电镀材料，分别进行了电镀实验和电镀前后电极丝线切割加工实验，通过电子显微镜和扫描电镜观察，对比了不同电极丝的表面形态，直观的说明了电镀Cu有利于保护电极丝表面；又通过能谱分析对不同电极丝表面所含元素进行分析，从所含元素角度说明了电镀电极丝补偿的可行性；之后使用Ansys仿真软件，得出了电极丝放电瞬间的温度分布云图，分析了放电后的散热过程，结合焓的运算得到放电瞬间热量传导情况，得出镀Cu后理论上只有10%左右的热量传递到电极丝上，大大减小了电极丝基体上的放电凹坑，对比了铜钼结合界面处放电点散热情况和单独钼表面散热情况，得到了各时间点的最高温度图，通过计算可知前者放电后散热速度是后者的1.5倍左右。上诉分析说明电镀电极丝可以提高其使用寿命。文中还对电镀法补偿电极丝进行了进一步理论分析，提出电镀补偿法的部分改进措施。最后提出附着法和复合电镀法两种补偿电极丝损耗的方法，简单分析了它们的可行性。 (2)电火花小孔加工一直存在排屑困难，，加工速度低的问题，因此提出螺旋电极电火花小孔加工方法，螺旋电极可使排屑容易，加工速度提高。分析了使用螺旋电极后放电间隙内流体的运动状态，使用Fluent仿真软件分别得出螺旋电极和普通电极间隙区域压力场和速度场，通过对比得出螺旋电极有利于排屑的结论。最后采用D703F高速电火花小孔加工机床进行实验，实验结果表明，螺旋电极电火花小孔加工速度最高可提高20%。文中还对实验所用螺旋电极做了详尽的分析，提出了改进措施和进一步研究的方向。
[Abstract]:Because of its unique advantages, EDM has an irreplaceable role in industry, because of its processing characteristics, the mechanical properties of the electrode requirements are low. This makes it possible to deal with various kinds of electrodes. In this paper, two common problems of EDM are proposed to improve the solution of electrode. The two common problems of EDM are as follows: Due to the nature of EDM, the loss of electrode wire is inevitable in high speed wire walking wire cutting, and it is also due to the recycling of electrode wire. Therefore, it will continue to finer and eventually break with the processing, which affects the normal conduct of high-speed wire cutting. In this paper, the electrode wire compensation method is proposed to reduce the loss of electrode wire. Finally, the purpose of prolonging the electrode wire life is achieved. In this paper, the loss of electrode wire is mainly compensated by electroplating method. The influence of electroplating on electrode wire is analyzed and the electroplating process is designed. Copper is selected as electroplating material. Electroplating experiment and wire cutting experiment before and after electroplating were carried out respectively. The surface morphology of different electrode wire was compared by electron microscope and scanning electron microscope. It is intuitively explained that Cu plating is beneficial to protect the surface of electrode wire. The elements contained on the surface of different electrode wires were analyzed by energy spectrum analysis, and the feasibility of the compensation of electroplated electrode wires was explained from the point of view of the elements contained. Then using Ansys simulation software, the temperature distribution cloud diagram of the electrode wire discharge moment is obtained, the heat dissipation process after the discharge is analyzed, and the heat conduction situation of the discharge moment is obtained by combining the calculation of the enthalpy. It is concluded that only about 10% of the heat is transferred to the electrode wire after Cu plating, which greatly reduces the discharge pit on the electrode wire matrix. The heat dissipation of the discharge point at the interface between copper and molybdenum was compared with that of the single molybdenum surface, and the maximum temperature diagram of each time point was obtained. The results show that the heat dissipation rate of the former is about 1.5 times that of the latter. The appeal analysis shows that the electroplating electrode wire can improve its service life. Further theoretical analysis of the electroplating compensation electrode wire is also carried out in this paper. In the end, two methods of compensating electrode wire loss by adhesion method and composite electroplating method are put forward, and their feasibility is simply analyzed. (2) there is always the problem of difficult chip removal and low machining speed in EDM. Therefore, the method of EDM machining with helical electrode is put forward, which can make chip removal easy. The flow state in the discharge gap after the use of spiral electrode is analyzed and the pressure field and velocity field in the gap region of spiral electrode and common electrode are obtained by Fluent simulation software. The conclusion that spiral electrode is advantageous to chip removal is obtained by contrast. Finally, D703F high speed EDM machine tool is used to carry out experiments, and the experimental results show that. The maximum machining speed of helical electrode EDM small hole can be increased by 20%. The helical electrode used in the experiment is analyzed in detail and the improvement measures and the direction of further research are put forward.
【学位授予单位】：太原理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TG484

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