摻雜奈米碳管的類鑽碳膜之機械與磨潤性質分析

THE MECHANICAL AND TRIBOLOGY PROPERTIES IN A CARBON NANOTUBE DOPED DIAMOND LIKE CARBON FILM

王肇翊(Chao-i Wang)

指導教授 ： 魏哲弘

大同大學/工程學院/機械工程學系所/碩士(2009年)

摘要

限制類鑽碳膜的發展通常是由於其高應力與低韌性的特性，為了改善類鑽碳膜，本研究利用奈米碳管旋轉塗佈於矽基材上，再由化學氣相沉積類鑽碳膜，形成含奈米碳管之類鑽碳膜。並以拉曼光譜儀、X光光電子能譜儀、水接觸角試驗等量測含奈米碳管類鑽碳膜之化學及表面特性。含奈米碳管類鑽碳膜之機械性質則使用奈米壓痕試驗與奈米刮痕試驗，且利用有限元素模擬探討奈米碳管對類鑽碳膜性質的影響。
實驗結果顯示，當奈米碳管含量增加時摻雜奈米碳管之類鑽碳膜硬度及楊氏係數也隨之提高，而摩擦係數則減少。在物性方面，薄膜的石墨鍵結sp2增加時，其表面越疏水，呈現石墨化現象。就附著力而言，摻雜奈米碳管類鑽碳膜的附著力在適當奈米碳管含量下，會增加其附著性，然而過多的奈米碳管則使其附著性變差。模擬結果顯示含水平碳管的類鑽碳膜硬度會提升，含直立碳管的類鑽碳膜則會降低薄膜硬度。且含奈米碳管類鑽碳膜，其奈米碳管含量與位置亦是影響整體機械性質的因素。由以上結果可知，加入奈米碳管會改變類鑽碳膜之機械與磨潤性質。

關鍵字

類鑽碳

並列摘要

The excellent properties of Diamond Like Carbon (DLC) films such as chemical inertness, wear protection and bio-compatibility is well know. However, its application is limited by the high internal stress and low fracture toughness. Many methods proposed to address these problems. The doping of CNT to increase the roughness and reduce internal stress is a feasible approach. In this thesis, multi-walled carbon nanotubes (MWCNTs) were spin coated on silicon wafer followed by DLC deposition with PECVD. The chemical properties of these CNT doped DLC films were analyzed by Raman spectroscopy, XRD, and contact angle measurement. The mechanical and tribological, properties were evaluated by nano-indentation and nanoscratch. The effect of the content and orientation of MWCNTs on the mechanical property of CNT-doped DLC is evaluated by a finite element analysis.
The results show the hardness, elastic modulus and contact angle are increasing and with increasing CNT content. The friction coefficient, the sp3/sp2 ratio and hydrogen content are decreasing for higher CNT concentration. The reduction of friction coefficient might be due the graphitization on the surface. The critical is increasing for 0.02%wt CNT but is decreasing for higher CNT contents. The decreasing critical load indicated the high concentration is disadvantage for adhesion.
The finite element analysis indicates that the orientation of the CNT has effect on the hardness. The vertical aligned CNT decreases the hardness while the horizontal CNT increases the hardness. The concentration, position also affects the overall mechanical properties for CNT doped DLCs. These results show that with CNT microstructure, the mechanical and tribological properties of DLC will be affected.

並列關鍵字

DLC

參考文獻

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