電火花放電法製備奈米金屬流體及其控制參數之研究

Preparation of Nano-Metal Fluid by Spark Discharge System and its Control Parameters Study

林弘修(Hong-Shiou Lin)

指導教授 ： 曾國雄

國立臺北科技大學/電資學院/電機工程系研究所/碩士(2012年)

摘要

以往對於金屬奈米顆粒的製備概念都是以化學的方式，以添加懸浮劑來達到奈米粒徑與濃度的控制；本研究提出利用放電加工機(EDM)，以電火花放電(ESDM)方式，透過電弧(Arc)將金屬材料裂解成奈米大小的顆粒，製程中無需添加化學藥劑，僅需利用純水或酒精等純溶液作為介質，透過設定電壓及電流等參數，並選擇各種放電脈寬時間(TON-TOFF)即可製備出懸浮於介電液中的金屬奈米顆粒，除了極高的製程效率，還可以大量生產並且不具有汙染問題，對於奈米材料的製備極具貢獻。然而奈米流體特性與製程參數之間有著緊密的關係，在放電期間通過電極的極間電壓、電流值、介電液與環境溫度等因素，皆會影響奈米流體的濃度與奈米顆粒的大小，故本論文將探討在各種放參數設定對於製備奈米金屬流體的影響，並選取純度99.9%的銀、銅、鈦與鋁作為主要研究的對象，最後利用可見光-紫外光光譜儀(UV-Vis)、粒徑表面電位儀(Zetasizer)與電子顯微鏡(SEM)等設備分析實驗結果；實驗結果說明了放電的脈寬時間控制，除了會影響各種金屬流體的濃度與流體在製程中的溫度上升幅度，也會影響顆粒的大小。另外，因鋁易氧化的特性，需加入特殊的製程設定才能順利地製備出鋁流體。

關鍵字

放電加工機 ； 電火花放電法 ； 奈米銀:奈米銅 ； 奈米鈦 ； 奈米鋁

並列摘要

In the previous studies, the preparation of metallic nanoparticles has almost used chemical methods by using the addition of surfactants to achieve the particle size and concentration controlling. In this study, the Electric Spark Discharge Method (ESDM) was proposed by Electric Discharge Machining (EDM). ESDM can be used to convert the metallic materials to suspended nanoparticles through the arcing process without adding any chemical additives. During the process only pure solution such as deionized water or alcohol etc was used, through the adjustment of the process parameters like voltage, current, and discharge on-off duration, the metal nanoparticles suspension in pure solution can be prepared. In addition ESDM also can be used for mass production and don’t have pollution problems. However, the characteristics of nanofluid have a close relationship with process parameters, include discharge voltage, current, dielectric fluid and temperature etc factors, that will be affect the particle size and the concentration of nanofluid. Therefore, this study will focus on 99.9% purity metals of silver, copper, titanium and aluminum to explore the different process parameters and their effects on the preparation of metallic nanofluid. The analysis equipments, such as UV-Visible spectroscopy (UV-Vis), particle size and surface charge analysis (Zetasizer) and Scanning Electron Microscope (SEM) were used to analyze the products. The results explain on-off duration can affect the concentration and temperature in the ESDM that can also affected the particle size. In addition, because of aluminum is easily oxidized, that must be added to special parameter that will can successful fabricated the aluminum fluid.

並列關鍵字

Electric Discharge Machining ； Electric Spark Discharge Method ； Nano Silver ； Nano Copper ； Nano Titanium ； Nano Aluminum

參考文獻

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