以電漿電弧方式製備奈米銅流體之研究
Abstract
本研究係研究以電漿電弧方式製備奈米銅流體 ，藉由過去文獻與研究的資料收集進而改良設計，系統架設、實驗測試、奈米微粒分析等多個步驟組成，以氣凝合成法來製備銅/水奈米流體（Copper/water nanofluid），選用能量高且能對各種金屬材料加熱蒸發之電漿電弧為加熱源，將所蒸發氣化之奈米微粒收集到流體收集器中，形成銅/水奈米流體以防奈米微粒因高溫而團簇或凝聚成較大尺寸在實驗過程中利用參數的設計，如電流及脈衝高低、流體收集器型式，試圖找出較佳製程參數，來獲得最小及均一粒徑的奈米微粒。
實驗過程分為兩階段，第一階段以不同電流參數，測試四種不同電流(50A，60A，70A，80A)型式之收集形態，巨觀以靶材融化度初步分析，判斷何種電流型式可能獲得較佳奈米微粒尺度，結果得知電流60A及70A時靶材融溶效果較佳；第二階段為以兩組不同電流參數60A及70A配合電漿電弧銲機之脈衝(pulse)功能，將所收集之銅/水奈米流體經超音波震盪器震盪後，再以 SEM、EDS、XRD、PH、導電度、熱傳係數、粒徑分析儀等儀器分析，以達最佳銅/水奈米流體製程。
經分析結果得知電流參數為 60A/25Hz 時平均粒徑在 548nm，電流參數為 70A/25Hz 時平均粒徑在 3500nm。最後對銅/水奈米流體作熱阻試驗，發現參數 70A/25Hz 在水溫 20℃時，熱阻下降率可達 30%。
The purpose of experiment is aim to a methods of nanofluid produce by arc plasma. Refer to previous research data and correction. Consist with several stages: preparation, modification, system installation, tested; use “Evaporation synthesi- zed condensation system” to implement copper/water nanofluid by selected high energy plasma arc that can vaporize any kind of metal as a heating source, collect vaporized nanoparticle into nanofluid collector. To avoid condensed bigger size of particle due to high temperature or cluster, take paramenter in consideration during the period of experiment; such as working current, collector function, trying to obtain process minimum and average nanoparticle. By mean of two stage experiment, base on different current parameter (50A, 60A, 70A, 80A) collector to gain the proper nanoparticle by target meterial melting situation. Preliminary analyze to determine what type of current maybe optimum parameter. Marcoscopic results show current 60A and 70A are optimum parameter for particle collect on stage one. In the second stage, base on fixed current used three different working current plasma arc torch pulse. Then stimulate with ultrasonic after that, analyze by SEM, EDS, particle size analyzer to define which process can produce perfect nanoparticle. As a result, working current 60A/25Hz average particle is 548nm, 70A/25Hz average particle is 3500nm, process copper/water nanofluid heating resistance test, found that heating resistance reach to -30% under water temperature 50℃, paramenter 70A/25Hz.
The purpose of experiment is aim to a methods of nanofluid produce by arc plasma. Refer to previous research data and correction. Consist with several stages: preparation, modification, system installation, tested; use “Evaporation synthesi- zed condensation system” to implement copper/water nanofluid by selected high energy plasma arc that can vaporize any kind of metal as a heating source, collect vaporized nanoparticle into nanofluid collector. To avoid condensed bigger size of particle due to high temperature or cluster, take paramenter in consideration during the period of experiment; such as working current, collector function, trying to obtain process minimum and average nanoparticle. By mean of two stage experiment, base on different current parameter (50A, 60A, 70A, 80A) collector to gain the proper nanoparticle by target meterial melting situation. Preliminary analyze to determine what type of current maybe optimum parameter. Marcoscopic results show current 60A and 70A are optimum parameter for particle collect on stage one. In the second stage, base on fixed current used three different working current plasma arc torch pulse. Then stimulate with ultrasonic after that, analyze by SEM, EDS, particle size analyzer to define which process can produce perfect nanoparticle. As a result, working current 60A/25Hz average particle is 548nm, 70A/25Hz average particle is 3500nm, process copper/water nanofluid heating resistance test, found that heating resistance reach to -30% under water temperature 50℃, paramenter 70A/25Hz.
Description
Keywords
奈米流體, 電漿電弧銲接, 奈米銅, Nanofluid, Plasma Arc Welding (PAW), Nanocopper