微细电火花加工数值模拟

文档编号:JX1617  文档字数:25406.页数:59 附任务书，开题报告，外文翻译

摘 要:
     微细电火花加工是一种微细特种加工工艺方法，在微机械以及微细结构加工领域具有举足轻重的地位。由于RC微能电源简单可靠，在微细电火花加工中得到了大量的应用。为了深入对微细电火花加工机理的认识，进一步提高微细电火花加工能力和效率，本文进行了相关的数值模拟和试验研究，在理论研究上和工程应用上取得了一些结论。
 本文主要研究内容如下：
 1．针对RC微能电源，建立了极间电场物理模型，采用数值模拟方法，探讨了电极形状、加工间隙等对电场分布的影响，掌握了相关的电场分布规律。
 2．根据传热学理论，建立了微细电火花加工工件表面的热物理模型，采用数值模拟方法，考虑热物性参数、对流换热、相变潜热等随温度变化的影响因素，掌握了工件表面温度场分布，得出了微细电火花加工极间温度场的分布规律。
 3．在上述研究基础上，采用微细电解方法在线制作柱状钨电极，合理选择工艺参数，进行了微细电火花加工试验，并分析了电参数对加工尺度和效率的影响，获得了三组应用于不同加工场合下优化的电参数。
 
 关键词：微细电火花加工，加工能力，效率，数值模拟，电场，温度场，电参数
                         
 
 ABSTRACT:
             Micro EDM(electric discharge machining) is a kind of special machining technique for micro machining .It has the pivotal status in the domain of micro machine as well as the micro structure processing . To raise the processing scale and the efficiency, this article has carried on the related numerical simulation and experimental study, and has made some progress in the fundamental research as well as the engineering application.
  Main content of this article is as follows:
 1. Using the numerical simulation method, electric field distribution influenced by the electrode geometry and the machining polarly has been discussed. Also, the related electric field distributed rule of the micro EDM has been got.
 2. According to heat transfer theory, the thermal physical model of work piece’s surface in micro EDM has been established, using the numerical simulation method, considering some factors influenced along with the changing of temperature such as the thermal natural parameter, the heat convection, the latent heat and so on, the temperature field distribution of the work piece’s surface has been grasped, and distributed rule of the interelectrode temperature field in micro EDM has been obtained.
 3. Basing the research foundation above, using the micro electric chemical machining to manufacture columnar tungsten electrode on-site, choosing the reasonable technological parameter, micro EDM experiments have been carried on. Also, the influence to the working accuracy and the efficiency caused by electrical parameter has been analyzed. What’s more, three groups optimized electrical parameter have been obtained to apply in the different manufacturing places.
 Key words: Micro EDM, Processing capacity, Efficiency, Numerical simulation, Electric field, Temperature field, Electrical parameter

目  录

第一章 绪论 1
1.1 引言 1
1.2 数值模拟在电火花蚀除机理研究中的现状 2
1.3 微细电火花加工的现状和发展 5
1.3.1 微细电火花微能电源的介绍 5
1.3.2 微细电火花加工的研究现状和发展 6
1.4 课题背景意义 9
1.5 本文主要内容及章节安排 10
第二章 微细电火花加工数值模拟 12
2.1 基于微能电源电火花加工极间电场分析 12
2.1.1 概述及物理模型 12
2.1.2 电火花电场数学模型 13
2.1.3 电火花电场的求解 14
2.1.4 ANSYS电场的仿真 16
2.1.5 影响电场分布因素的探究 20
2.2 放电状态下的极间的物理过程 22
2.2.1 温度场模型的建立 22
2.2.2 温度场模型的求解 24
2.2.3 温度场的仿真 27
2.3 本章小结 32
第三章  微细电火花加工试验研究 33
3.1 试验设备—微细电火花机床介绍 33
3.2 试验电极的制作 34
3.3 常用材料性质 35
3.4 极性及电参数对微细电火花加工的影响 36
3.4.1极性对微细电火花加工的影响 36
3.4.2 电容对微细电火花加工的影响 39
3.4.3 空载电压对微细电火花加工的影响 40
3.4.4 脉宽对微细电火花加工的影响 42
3.4.5 脉间对微细电火花加工的影响 45
3.4.6 试验结果及讨论 47
3.5 本章小结 50
第四章 总结和展望 46
4.1 全文总结 46
4.2 研究展望 47
参考文献 48
致谢 51

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