利用導電性監測複材膠合接口濕熱老化

Abstract

本研究為透過非破壞監測膠合接口於溫濕熱環境內部損傷程度。將碳纖維強化基板塗佈含有奈米碳管的環氧樹脂，使其試片具有導電性，並於試片兩側埋入銅箔接膠帶，以便監測其試片電性資料。

試片於高溫高濕環境及高溫低濕環境試驗中，監測試片於不同天數下，電性變化情形，以及經過濕熱老化後，機械性質下降的程度。抑或是透過電性的趨勢或改變，掌握其破壞的機制，能否觀察出介面弱化與基材弱化相對應到的電性趨勢，最後也透過SEM觀察其破斷面微觀破壞情形。

實驗結果顯示，利用電壓監控試片於高溫高濕及高溫低濕過程，僅能做定性分析，不太適合用來做定量分析。透過SEM觀察到，高溫高濕試片複材纖維有明顯樹脂塑化、纖維拔出(Fiber Pulled-Out)及介面弱化現象，高溫低濕試片複材本身無纖維拔出(Fiber Pulled-Out)，搭接劑斷面上有明顯脆性斷裂痕跡。

This study deals with monitoring single lap CNT-epoxy joints of carbon fiber reinforced plastics (CFRP) by conductivity in hygrothermal environment. The adhesive is conductive because it’s made of epoxy resin mixed with carbon nanotubes. The material is of the sheet in this experiment is made of CFRP by thermoforming .For voltage change measurement, copper foil is embedded in CFRP and welded with wires to measure the voltage change of entire adhesive joint.

The specimen will be set in hygrothermal environment and observe the voltage changes and mechanical properties during the experiment. .Find out the relationship between conductivity and failure mechanism. Using SEM to analyze materials’ fracture surface.

The result of the experiments showed that voltage change measurement could do qualitative analysis to the load and aging experiment period. The spcimens of high temperature and moisture experiment reveals resin plastic、Fiber Pulled-Out and weakening of interface but it doesn’t reveal in the specimens which is set in high temperature and low moisture environment. It has been observed that the brittle fracture trace on the adhesive joint.