微細電火花加工數值模擬

論文編號:JX1617  論文字數:25406.頁數:59 附任務書，開題報告，外文翻譯

摘 要:
     微細電火花加工是一種微細特種加工工藝方法，在微機械以及微細結構加工領域具有舉足輕重的地位。由于RC微能電源簡單可靠，在微細電火花加工中得到了大量的應用。為了深入對微細電火花加工機理的認識，進一步提高微細電火花加工能力和效率，本文進行了相關的數值模擬和試驗研究，在理論研究上和工程應用上取得了一些結論。
 本文主要研究內容如下：
 1．針對RC微能電源，建立了極間電場物理模型，采用數值模擬方法，探討了電極形狀、加工間隙等對電場分布的影響，掌握了相關的電場分布規律。
 2．根據傳熱學理論，建立了微細電火花加工工件表面的熱物理模型，采用數值模擬方法，考慮熱物性參數、對流換熱、相變潛熱等隨溫度變化的影響因素，掌握了工件表面溫度場分布，得出了微細電火花加工極間溫度場的分布規律。
 3．在上述研究基礎上，采用微細電解方法在線制作柱狀鎢電極，合理選擇工藝參數，進行了微細電火花加工試驗，并分析了電參數對加工尺度和效率的影響，獲得了三組應用于不同加工場合下優化的電參數。
 
 關鍵詞：微細電火花加工，加工能力，效率，數值模擬，電場，溫度場，電參數
                         
 
 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  錄

第一章 緒論 1
1.1 引言 1
1.2 數值模擬在電火花蝕除機理研究中的現狀 2
1.3 微細電火花加工的現狀和發展 5
1.3.1 微細電火花微能電源的介紹 5
1.3.2 微細電火花加工的研究現狀和發展 6
1.4 課題背景意義 9
1.5 本文主要內容及章節安排 10
第二章 微細電火花加工數值模擬 12
2.1 基于微能電源電火花加工極間電場分析 12
2.1.1 概述及物理模型 12
2.1.2 電火花電場數學模型 13
2.1.3 電火花電場的求解 14
2.1.4 ANSYS電場的仿真 16
2.1.5 影響電場分布因素的探究 20
2.2 放電狀態下的極間的物理過程 22
2.2.1 溫度場模型的建立 22
2.2.2 溫度場模型的求解 24
2.2.3 溫度場的仿真 27
2.3 本章小結 32
第三章  微細電火花加工試驗研究 33
3.1 試驗設備—微細電火花機床介紹 33
3.2 試驗電極的制作 34
3.3 常用材料性質 35
3.4 極性及電參數對微細電火花加工的影響 36
3.4.1極性對微細電火花加工的影響 36
3.4.2 電容對微細電火花加工的影響 39
3.4.3 空載電壓對微細電火花加工的影響 40
3.4.4 脈寬對微細電火花加工的影響 42
3.4.5 脈間對微細電火花加工的影響 45
3.4.6 試驗結果及討論 47
3.5 本章小結 50
第四章 總結和展望 46
4.1 全文總結 46
4.2 研究展望 47
參考文獻 48
致謝 51