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    Please use this identifier to cite or link to this item: http://ir.lib.ncu.edu.tw/handle/987654321/77887


    Title: 三維熱流場對不同形式電化學微加工之影響;The Influence of 3D Thermofuilds Field on Different Types of Electrochemical-Micro Machining
    Authors: 林宏霖;Lin, Hung-Lin
    Contributors: 機械工程學系
    Keywords: 遮罩式電化學加工;有限元素法;電場;熱流場;模擬;through-mask electrochemical micro-machining (TMEMM);finite element method;electric field;thermofluids field;simulation
    Date: 2018-07-25
    Issue Date: 2018-08-31 15:01:58 (UTC+8)
    Publisher: 國立中央大學
    Abstract: 遮罩式微電化學加工(Through-Mask Electrochemical Micro-machining,TMEMM)最大的特色在於,刀具不受形狀所限,只需在遮罩上開孔所需的圖案,即可同時加工各種形狀。且加工速度快,無電解液回收問題,較為環保,適合運用在大面積陣列孔加工上。
    微電化學加工是由許多不同物理現象所組合而成。以現今之遮罩式微電化學加工之研究中,大多數是以二維單一物理場做模擬,在利用實驗進行加工後之分析。因此,本文嘗試利用有限元素法創建熱流場與電場之三維模型,討論不同流向、施加電壓、電解液流速和改良式模型對加工外形之影響。
    模擬結果顯示,相同流速下,電壓越大,平均半徑、平坦度、平均半徑和真圓度也會隨之變大,而正向流在真圓度方面優於側向流;相同電壓下,流速越快,平均深度、平坦度和平均半徑會隨之下降,真圓度則是在側向流流速0.05m/s和正向流流速0.5m/s最好;改良式加工在固定電壓時,正向流的平坦度與平均半徑都較優於側向流,平均深度與真圓度則較差;改良式加工在加工深度上都優於一般式加工,但遮蔽效應與較小加工間隙使平坦度較差,而真圓度則是只有側向流改良式加工優於一般式加工。
    ;In the Through-Mask Electrochemical Micro-machining (TMEMM), one tool can be used to machine work-pieces of different shapes or patterns if different masks are provided. The designing time and cost for tools is largely reduced. The electrolyte recycle doesn’t have problem and the process is very fast. Therefore, TMEMM is suitable in machining arrays of holes in a large area.
    The process of TMEMM involves complex physical phenomena. Nowadays, the simulation on TMEMM is primarily restricted in the influence of electric field, plus the experimental verification. In this study, the 3D electric field is implemented with the thermal and flow fields and solved by the finite element method. The effects of flow directions, applied voltages, and electrolyte flow rates on the machined shape are investigated. A modified through mask is proposed and simulated, and comparisons of the machining profiles by traditional and modified masks are made.
    Results show that the average depth, flatness, average radius and roundness are all increased as the applied voltage is increased. The roundness in the forward flow is better than that in the lateral flow. As the flow rate is faster, the average depth, flatness and average radius will be decreased. The roundness is at its best at flow rate of 0.05m/s in the lateral flow and 0.5m/s in the forward flow. In the modified TMEMM process, under the same applied voltage, the flatness and average radius in the forward flow are better than that in the lateral flow, while the average depth and roundness are worse. Compared with the traditional TMEMM, the modified TMEMM can yield better average depth, however the shadow effect and small inter electrode gap will let its flatness becomes worse. The modified TMEMM with lateral flow results in better roundness than the traditional EMEMM does.
    Appears in Collections:[Graduate Institute of Mechanical Engineering] Electronic Thesis & Dissertation

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