7075鋁合金為質輕、具高強度的熱處理型鋁合金，目前多應用在國防與航空工業等，如飛機的機翼。然而因該合金成形性較不如6xxx系列佳，難以製造出形狀複雜且擁有7xxx系列高強度的製品。因成形性和拉伸延性有密切關係，因此本研究嘗試以7075鋁合金擠形棒材進行高溫人工時效處理改善拉伸延性，以提供易加工的前處理，並和一般常用改善7xxx系列加工性的完全退火材進行比較，以及利用韋伯解析探討兩者處理對於拉伸延性的可靠度表現。
高溫時效可使材料時效所需時間縮短，且此時材料內大多以η平衡相為主，進而使析出強化減弱、延性可獲得提升。由實驗結果顯示，490℃、1小時固溶處理後，經280℃持熱12時有約25%的最佳總延伸率，高於完全退火處理的21%；從金相組織觀察可知，高溫時效材比完全退火材少了許多粗大的鋁-銅晶出相，降低微空孔的生成，延遲破斷發生。此外，該高溫人工時效條件之亦高於完全退火材，故對於塑性加工上有其優勢。
可靠度表現方面，以具有最佳TE的高溫時效材和完全退火材進行比較。結果顯示兩者皆為破壞遞增型且韋伯模數m值符合應用需求。然而高溫時效具較高的位置參數，使得其分佈曲線整體右移，在高TE的可靠度大於完全退火材，故就應用層面來說，高溫人工時效較完全退火可提高7075鋁合金在拉伸延性上的可靠度。

7075 aluminum alloy is light weight and with higher strength among aluminum alloy, and wildly use in aerospace industry, such as plane wing. To increase formability for broadening applications of this alloy, fully annealing normally has been wildly employed in industry, but it takes much time in process; for this reason, we use another method, high temperature aging (HTA) treatment to create another treatment to improve it. HTA reduces time of treatment and lower strength by formation of non-coherent η phase in matrix, so as to increase tensile ductility for better formability. Results show that the best parameter of HTA increasing tensile ductility is HTA280-12, and it lacked of lots of large particles, Al-Cu phase which is usually seen in fully annealed AA7075. The HTA280-12 had better reliability analyzed by Weibull distribution than fully annealed.

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