本研究以鋁合金7XXX系中AA7039添加0.05 wt.%的Sc；AA7049添加0.106 wt.%的Sc、0.113 wt.%的Zr和2.26 wt.%的Cu，經由不同條件的熱處理程序並進行機械性質測試及顯微組織觀察，以探討7XXX系之鋁合金添加微量Sc、Zr和Cu對其材料性質之影響。並期望此一研究之成果日後能運用於提升7XXX系鋁合金之材料強度並增加其應用的廣泛性。 由實驗結果顯示：AA7039在添加微量Sc後，常溫抗拉強度無論有無經過退火皆有400MPa以上的表現，而AA7049在添加Sc、Zr和Cu後，其抗拉強度為522MPa，且兩者皆在滾軋率R=20%有較強之抗拉強度。而120、150℃溫度下之T6人工時效處理其拉伸試驗結果顯示：AA7049加Sc、Zr和Cu之抗拉強度高達660MPa比AA7039加Sc之抗拉強度466MPa提升許多，主要是其結構上含有散佈強化和析出物較多。 在高溫拉伸部分，AA7039加Sc在溫度400℃以應變率1×10-2S-1下，伸長量124%為最佳效果。AA7049加Sc、Zr和Cu在溫度400℃以應變率5×10-3 S-1，伸長量可達244%，主因在於含有較多晶粒細化劑Sc、Cu和Zr。並且由金相圖中可明顯觀察到AA7049加Sc、Zr和Cu經過500℃、1hr退火，晶粒有明顯的細化現象且有消除擠製流線的作用。 There are two materials in our research. The first one, add 0.05 wt.% Sc into Al-Zn-Mg and name it Al-0.05Sc. Another one, add 0.106 wt.% Sc、0.113 wt.% Zr and 2.26 wt.% Cu and name it Al-0.1ScZr2.2Cu. They were rolling reductions of 20、40% rolling process and artificial aging at temperature 120℃ and 150℃ that in order to discuss precipitation affect in the materials, followed by an extrusion for plates. The superplastic properties were examined in tension at temperature ranging from 300 ~ 500℃ and strain rates ranging from 1×10-2 ~ 1×10-4 S-1. The microstructure of Al-0.1ScZr2.2Cu alloy by annealing 500℃ for 1hr extruded condition is consisted of equaxied subgrain structure, and grain size is 4μm. The effect of adding Sc and Zr were resisted to recrystalize in Al alloys. After the artificial aging, both of the alloys increase to HRB17 respectively. Using artificial aging to find peak-aging and use this parameter to test tensile experience. After past peak-aging, the UTS of Al-0.1ScZr2.2Cu is 660MPa. And the result of 20% rolling reduction exhibit that both of the alloys is the better UTS, 455MPa and 510MPa. During high temperature superplasticity, the second phase particles consist of Sc, Zr and Cu elements, which play an important part for tensile testing. The best situation of elongation is 244% at temperature 400℃ and strain rate 5×10-3 S-1.
