氧化鋁陶瓷材料具有相當優良的物理、化學和機械性質，是目前最廣泛被使用的陶瓷材料之一。除了陶瓷粉體容易取得及成本較低的優點外，氧化鋁的高強度、熱穩定性及低熱傳導性近年來也適用於高溫結構體及基板的應用。但氧化鋁陶瓷仍和一般常見的陶瓷相同，擁有低延展性、低韌性的缺點，為改善此情形，其可利用更高的燒結溫度及施以加壓燒結，得到緻密之燒結體，或添加金屬相製作成氧化鋁基的陶瓷/金屬複合材料，預期以添加韌化相之方式，大幅度提升其破壞韌性值。
本研究是以純氧化鋁粉末中混入不同體積配比的石蠟為起始粉末，壓製成生胚後於大氣氣氛中脫脂、燒結成多孔且連通的氧化鋁預形體，再以擠壓鑄造法，將鋁合金熔液以外加機械壓擠入氧化鋁預形體中，製成不同氧化鋁/鋁合金體積比例之複合材料。試片經裁切、研磨及拋光後，測量其物理性質及機械性質，並研究添加不同體積配比的第二相，對其物理性質及機械性質的影響，再將試片做適度的加工，以光學顯微鏡及電子顯微鏡觀察其微結構與破壞表面，探討複合材料之破壞機構。
經實驗分析後得知，以擠壓鑄造法製作氧化鋁/鋁合金複合材料，經電性及影像分析結果可得知，本研究可製作出陶瓷及金屬兩相均勻分佈且相互連通之複合材料。氧化鋁/鋁合金複合材料之機械性質分析中，硬度值隨金屬相體積百分比的增加而降低，其四點彎曲強度值隨金屬相體積百分比的增加而先增加後降低，而破壞韌性值隨金屬相體積百分比的增加而增加，其中氧化鋁/A356鋁合金複合材料為本研究中最佳物理及機械性質之複合材料，進而以物理性質及微結構觀察的方式探討其性質較佳之原因。
研究中發現氧化鋁/ A356鋁合金複合材料之物理性質及機械性質的關連性，並由前人之研究中觀察到的同樣現象，可推測殘留應力之形成是由於複合材料由製程高溫降低至室溫時，高熱膨脹係數之鋁合金相包圍擠壓氧化鋁陶瓷相所致，因此殘留應力應產生於陶瓷及金屬相的介面處。研究後續以有限元素法模擬分析複合材料中，金屬及陶瓷兩相間因熱膨脹係數的差異而產生之殘留應力；且以高角度X-ray繞射分析法，分析複合材料中存在的殘留應力實驗值，並比較理論值及實驗值的差異之處。之後分析陶瓷/金屬兩相間的接觸面積，研究結果發現，兩相間接觸面積的多寡將會影響複合材料中殘留應力的大小。由此可解釋以有限元素法模擬分析，及高角度X-ray繞射分析法研究複合材料中，所得到不同殘留應力數值的原因。最後討論殘留應力的存在，對於氧化鋁/ A356鋁合金複合材料之微結構及機械性質的影響，並綜合討論複合材料中，強化及韌化機制的存在及影響。

Aluminum oxide (Al2O3) is a hard refractory ceramic, which has been investigated for high temperature structural and substrate applications because of its good strength and low thermal expansion coefficient. Nevertheless, like other monolithic ceramics, Al2O3 is apt to suffer from low ductility and low fracture toughness. Therefore, metals (e.g. aluminum, cobalt, and niobium) or alloys are added to ceramics to improve their toughness.
This study aims at investigating the physical, mechanical properties and fracture behaviors, and internal residual stresses in metal reinforced ceramic matrix composites (CMCs). A356, 6061 and 1050 aluminum alloys were infiltrated into the aluminum oxide (Al2O3) preforms in order to fabricate Al2O3/A356, Al2O3/6061 and Al2O3/1050 composites, respectively, with different volumes of aluminum alloy content using the pressure infiltration technique of squeeze casting. The contents of aluminum alloy in the composites were 10 to 40 percent by volume. For all different Al alloy composites, the hardness decreased dramatically, the four-points bending strength increased, the fracture toughness increased, and the resistivity decreased dramatically with increasing Al alloy content in the composites, respectively. From SEM microstructural analysis and TEM bright field images, the porous ratio and the relative density of the composites were the most important factors that affected the physical and mechanical properties, and there are four different toughening mechanisms affected the toughness of the composites, i.e. metal phase increased, crack bridging, crack deflection, and crack branching in the composites.

Values of coefficients of thermal expansion (CTEs) were found to vary significantly with temperature, indicating an influence of the flow characteristics of the metal. Comparisons are made with well known methods for predicting CTEs values of metal/ceramic composites. The overall strain was found to increase with temperature and scaled proportionally with the metal content of the composite. Comparisons were also made with non-infiltrated porous ceramic preforms and a pure metallic sample. The uniform heating and cooling curves for the composite samples were found to exhibit hysterisis. The residual stress analysis and failure simulation were performed based on thermomechanics and the finite element method (FEM). This analysis is often utilized for the analysis of stress distribution or deformation of a structure. High angle X-ray and CTEs mismatch equation analysis were utilized to analyze the residual stresses at the ceramic / metal interface of the Al2O3/A356 composites. The relationship between residual stresses and the contact area of the ceramic / metal interface are also discussed.

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