自石油危机以来

自石油危机以来 摘要 自石油危機以來,車輛輕量化已被公認為車輛技術發展的主流之一,而三明治夾心板結構具有質量輕、高抗壓、高衝擊以及較佳的隔音隔熱效果,因此逐漸被用來取代一些傳統材料,例如:在汽車業、航空業..等。尤其在航太方面,三明治夾心板是最為常用的材料結構。 本論文研究製備一種以鎂基複合材料作為面板並搭配鋁合金的心材之三明治夾心板為目標。在此三明治夾心板中,面板採用鎂基複合材料,藉著強化相的影響來改善,使材料變成具有較高彈性係數、降伏強度、潛變壽命、疲勞極限的鎂基複合材料並依此做為面板的材料;再與搭配蜂巢鋁合金材料來製備三明治夾心板的研究是本論文的目標。 本研究在面板材料上使用碳化矽顆粒材料做為強化相,將此強化相以熔煉的方式加入AZ91D鎂合金中,並經由攪拌達到強化相均勻分散的結果,最後再利用熱壓延的方式將材料壓延成薄板並研究其機械性質以備面板使用。鋁合金蜂巢結構材料作為心材,與鎂基複合材料製成的面板,利用熱壓釜方式結合形成三明治夾心板結構,並以三點彎曲測試來測量及研究此三明治夾心板結構的機械性質。 而由結果顯示,鎂基複材面板在硬度上有提升,不過強度上卻下降,而對於三點彎曲測試結果則可發現,添加Vol. 2.91%與Vol. 4.76%碳化矽之面板製備而成的三明治夾心板在比強度與比彎曲強度上,略高於使用鋁合金面板之三明治夾心板。 關鍵字: 複合材料、鎂合金、三明治夾心板、碳化矽、彎曲強度 Abstract Due to the petroleum crisis, vehicle weight reduction has been recognized as the main stream of the vehicle technology development. The structure of the composite sandwich material has advantage in light weight, high resist compression, high impact, better effectiveness of noise suppression and thermal Insulation, so it has been used to replace some traditional materials gradually, i.e. in automotive industry, airport industry…etc. The sandwich composite was very common, especially in aerospace industry. The aim of this paper is to make the composite sandwich material formed with the faceplate of the magnesium alloy matrix composite materials and aluminum alloy core. In magnesium alloy matrix composite, the reinforcement was used to strengthen elastic modulus, yield strength, creep life and fatigue limit. And magnesium alloy matrix composite has been used to be the faceplate to fabricate the sandwich composite with the aluminum alloy honeycomb core. The silicon carbide (SiC) is used to be the reinforcement in this study, the reinforcements are added into the Mg alloy by the smelting method, in order to make the particles spread uniform, the melt was stirred. Finally, the materials were pressed to form thin broads with the hot press and observed the mechanical properties. The honeycomb structure of aluminum alloy is prepared to be the core. And it was combined with faceplates of the magnesium alloy matrix composites to form the sandwich composite by the hot press method. And the mechanical properties of sandwich composites are observed with the bending test. Observing the results in this investigation, the faceplates of the MMCs were increased in hardness, but decreased in strength. In the results of bending test, it can be found that the specific strength and specific bending strength of sandwich composites fabricated with the faceplates of magnesium alloy added silicon-carbide (SiC) reinforcements are a little higher than with the faceplates of aluminum alloy. Keywords: Composite, Magnesium Alloy, Sandwich, Silicon Carbide, Bending Strength