以奈米壓痕探討陽極氧化鋁之機械性質與奈米孔徑之相關性

Abstract

陽極氧化鋁因具有良好的物理特性與化學特性，而且低成本與製造容易。廣泛應用在催化、化學與生物感測器、自組裝的模板、過濾器、奈米流體晶體管、濕度感測器、細胞培養、超級電容器。奈米壓痕技術由於據有奈米位移解析度，以及量測方法之均一性與簡易性等優點，故近年來被廣泛被應用於各種類型之材料測試上，應用層面可包含材料之彈性模數、硬度(降伏強度)、破壞特性等研究領域。本研究運用陽極氧化處理技術製作陣列式不同孔徑之奈米孔洞，並以奈米壓痕機(Nanoidentation)量測陣列式不同奈米孔洞之機械強度，並探討五種不同奈米孔洞機械強度之差異。奈米孔洞其孔徑在 50nm、150nm、250nm、350nm、450nm 。並使用奈米壓痕量測表面微結構之機械強度，並探討孔徑變化與機械強度之間的關係。其中彈性模數、硬度在壓痕速率0.05um/s下差異性相當小，但是在壓痕速率0.025um/s下時會發現差異性相當大。而回彈量與壓痕速率成正比。潛變與壓痕速率成反比，與孔徑大小無關係。Because Anodized Aluminum Oxide (AAO) has good physical properties and chemical properties, low-cost and easy to manufacture, it was widely used in catalysis, chemical and biological sensors, self-assembled templates, filters, nanofluid transistors, humidity sensors, cell culture and super capacitors. Due to nanometer displacement resolution, and the advantage of simplicity, nanoindentation has been used widely apply in various types of materials testing which includes the determination of elastic modulus, hardness (yield strength). The study investigates the mechanical properties of AAO with different size of nanopores. Array of different size of nanopores was made using anodized technology. The diameters of nanopores were 50 nm, 150 nm, 250 nm, 350 nm and 450 nm. The mechanical strength was measured using nanoindentation. The relationship between the different size of nanopores and the mechanical strength was investigated. The study found that the speed of nanoindentation was 0.05um/s which had no significant effect on the mechanical properties, such as elastic modulus and hardness. But for the speed of nanoindentation was 0.025um/s which had big significant effect on the mechanical properties. Rebound rate was proportional to the speed of nanoindentation. Creep rate was inversely proportional to the speed of nanoindentation. There is no relationship between creep rate and size of nanopores.