本研究主要是探討航空複合材料的界面性質和蜂巢結構件開發研究，在界面性質方面，分為兩個研究主題，第一部份為飛機常用之鋁合金結構件之界面性質研究，於壓力釜中以環氧樹脂基片膠膠合四種經過不同表面處理程序之鋁合金，藉由SEM觀察鋁合金表面之微結構型態、剝離強度試驗及接著面之破壞模式，分析不同的表面處理對膠合性能之影響，結果顯示，經由鉻酸陽極化處理之鋁合金於常溫及低溫(-55℃)時，均能有最佳的膠合強度，熱酸浸蝕之鋁合金則僅能於常溫時展現良好之膠合強度，硫酸陽極化及硬陽極化之膠合強度最差，其因乃是鉻酸陽極化所形成之氧化皮膜，有更多孔型之微結構，可增加膠合之面積而強化膠合強度；第二部份則是飛機常用之碳纖維積層結構件之界面性質研究，特別是疊層順序與疲勞之關係研究，透過機械性質測試及疲勞壽命及疲勞破壞後之型態研究，結果顯示，單向纖維疊層有最大之拉伸強度，正負45度方向之纖維疊層有較大之拉伸應變，在高應力區所有試片的疲勞壽命皆低於103循環，在低應力區則皆高於106循環， [908]s之纖維疊層之疲勞壽命最低，而[04]s疊層則具有最長之疲勞壽命，透過SEM的觀察，破壞面之破壞模式，包含脫層、基材裂痕及纖維破壞等可加以確認，SEM的圖片顯示疲勞破壞與疊層順序有密切的關係存在。
蜂巢結構件開發主要是熱固性與熱塑性飛機地板之物性研究，其中，熱固性飛機地板係由玻纖強化酚醛蒙皮和Nomex蕊材及鋁合金嵌入件所組成，熱塑性飛機地板則由玻纖強化PEI蒙皮和Nomex蕊材及PEI嵌入件所組成，結果顯示，熱塑性板件具有極為優秀之低吸水性，熱固性板件之吸水率約比熱塑性板件高七倍，乃因熱塑性板件之特性，可以熱折封邊，以降低水氣進入蕊材，反觀熱固性板件因為架橋結構，而無法再次加工，此外，熱塑性板件同時展現出較佳之撥離強度，大約是熱固性板件的三倍，在耐燃方面，熱固性板件則較熱塑性板件好，但兩者都可達到美國航空總署的耐燃要求，總之，熱塑性板件做為飛機地板使用時，除能提供優於熱固性之物性外，其耐燃與低毒性亦相當優異。

This study is to investigate the interfacial properties of aerospace composite and developing on honeycomb sandwich structure panel. There will divide into two research themes in the interfacial properties part of this paper. Adhesively bonded aluminum laminates are used in aerospace applications. The first part focuses on studying the interfacial properties of adhesively bonded aluminum laminates which are used in aircraft structure parts. Four different surface treatments were performed on aluminum sheets that were then bonded with an epoxy-based film adhesive in an autoclave to achieve good adhesion. Specimens were examined to determine the microstructure of the porous oxide layer on the aluminum sheet surface and its effects on the bonding performance through Scanning Electron Microscopy (SEM), peeling strength and failure mode analysis. Based on the failure modes of the bonded surfaces, the peeling strength, and an analysis of the microstructure of the porous oxide layer, this study showed that chromic anodizing had the best bonding performance in normal- or low-temperature environments, whereas sulfuric anodized and hard anodized exhibited the worst bonding performance. Hot etching exhibited good bonding performance only in normal temperature but fail in low-temperature compared to those treated by chromic anodizing. The chromic anodizing surface treatment can produce more pores on the oxide layer of aluminum sheet surface, which can enlarge the bonding areas and consequently enhance its bonding performance. The second part focuses on studying the interfacial properties of carbon fiber laminates which are used in aircraft structure parts, especially for understanding the relationship between the stacking sequence and fatigue life of carbon fiber laminates. By investigating mechanical properties, fatigue life and the morphology of after fatigue fracture of carbon fiber/epoxy composite, the results show that the unidirectional carbon fiber laminate has the maximum tensile stress. Moreover, the laminate with ±45 degree plies can improve the tensile strain. The fatigue life of all specimens was shorter than 103cycles under high cyclic stress level, and longer than 106cycles under low cyclic stress level. Laminates with [908]s stacking sequence had the shortest fatigue life under high and low cyclic stress, while the [04]s laminate had the longest fatigue life. A number of fatigue damage models, including delaminating, matrix cracking and fiber failure, have been indentified by scanning electron microscopy (SEM). The SEM micrographs showed that the morphology on the cross section, after fatigue fracture, was significantly correlated to the stacking sequence.
For developing on honeycomb sandwich structure panel, this study focuses on the physical properties of honeycomb sandwich panels of aircraft floors and to compare the difference in properties between thermoset glass/phenolic facing honeycomb sandwich panels separated by a Nomex core with aluminum inserts and of glass/ PEI facing honeycomb sandwich panels bonded to a Nomex core with PEI inserts. This study showed that thermoplastic honeycomb sandwich panels exhibited excellent low water absorption, which was nearly seven-time lower than thermoses. The thermoplastic panels can be thermofolded downward to seal the edges, while thermosets are cross-linked when heated and cannot be re-melted or re-formed. The thermoplastic panels also show a good performance on drum peel strength, which is over three-times as themosets. On the flammability, thermoset panels demonstrated a little better fire resistance than thermoplastics. Both of them pass the federal aviation regulations. To sump up, thermoplastic honeycomb sandwich panels can provide high performance properties and were significantly less flammable and toxic when be used for aircraft floor.

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