2024鋁合金因其良好的強度及重量比而廣泛地應用於航太工業，同時它也是一種屬於熱處理後的鋁合金。然而，據研究2024鋁合金易受到多種腐蝕所侵害，其中之一包含應力腐蝕破裂(SCC)。因此，為了探討應力腐蝕破裂於2024鋁合金上的行為，本次將以單軸拉伸試驗做為主軸，並利用金相分析、電子掃描式顯微鏡(SEM)及電化學測試加以分析。熱處理條件則是將試片加熱至495 oC後水淬，並於室溫中進行自然時效處理96小時。在應力腐蝕破裂的部分，則主要是在pH值分別為2.8及6的0.1 M NaCl水溶液中，以拉伸應力300 MPa及340 MPa下進行。
藉由金相分析可知，此合金的微結構中富含Al2CuMg (S-phase)；而由SEM影像分析可知再經熱處理的試片中，相較於未熱處理的試片則有更嚴重的沿晶破裂及均勻腐蝕，證實了應力腐蝕破裂的初始階段。同時，隨著深度增加，破裂的部分會轉變成更小的沿晶破裂。

Due to good strength and weight ratio 2024 aluminum alloy widely used in aerospace industry. This type of aluminum alloy is a heat treatable alloy. Nevertheless 2024 aluminum alloy was reported susceptible to several types of corrosions including stress corrosion cracking (SCC). Therefor to understand the stress corrosion cracking behavior of this alloy, several types of experiments were being conducted, using Stress corrosion cracking testing on uniaxial load as a primary technique, then metallography analysis, Scanning Electron Microscope (SEM), and electro-chemical testing. As for the heat treatment, the specimen was heated until 495°C then water quench and natural aging in room temperature for 96 hours. 0.1 M NaCl with concentration of acidity of 2.8 and 6 solution was being used as the corrosive environment during the stress corrosion cracking testing.
The load that being applied on the testing were 300 MPa and 340 MPa. The metallography analysis showed that the microstructure of this alloy contained mostly of Al2CuMg (S-phase). On the other hand the SEM image analysis testing on the heat treated materials showed more severe inter-granular cracking and uniform surface corrosion compared to as-received materials, indicating the initial stage of stress corrosion cracking. As the depth increase, the cracking then transform into finer inter-granular cracking.

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