本研究主要是探討7075-T6鋁金滾軋板材在不同晶相方位、應變速率與溫度下之塑變行為與顯微差排結構特性。實驗試片為圓柱形，分別沿著晶滾軋後之沿晶(Longitudinal)方向和垂直沿晶(Transverse)方向加工。再以霍普金森撞擊試驗機(split-Hopkinson pressure bar, SHPB)於應變速率103s-1、2×103s-1、3×103s-1和5×103s-1之條件，分別測試室溫與高溫350℃下沿晶方向試件和室溫下垂直沿晶方向之試件。
實驗結果顯示，7075-T6鋁合金之機械性質與顯微結構受晶向、溫度與應變速率相當程度之影響。兩種不同晶向方位之試片皆為隨著應變速率之提升，其塑流應力值、應變速率敏感性係數和加工硬化係數亦隨之增加；然而熱活化體積會與應變速率呈現反向關係。
此外，以室溫25℃沿晶方向試件為控制組、高溫350℃沿晶方向與室溫垂直沿晶方向之試件為二實驗組，比較三組機械性質差異。可歸納出垂直沿晶方向之強度在低應變速率時較高，但是加工硬化率與差排滑移能力不佳，使得在高應變速率下之加工硬化強度表現較沿晶方向來得差。而比較高溫與室溫沿晶方向之行為表現，得知高溫之加工硬化率較室溫來得低，但由應力-應變特性得知，其對應變速率低至高的差異較為敏感，高應變速率下之加工硬化程度較低應變速率來得高。
最後藉由實驗之結果，依晶相方位分別求出Zerilli-Armstrong組構方程式之常數，並證明此公式溫度涵蓋範圍可由25至350℃。OM與TEM觀察顯微結構組織，整理計算實驗之晶粒大小、差排環尺寸與差排密度，以修正後之Hall-Petch關係式得出應力值與顯微結構之關係。

In this study, 7075-T6 aluminum alloy was examined under different grain directions, strain rates and temperatures using split-Hopkinson pressure bar in order to investigate its dynamic deformation behaviors and microstructure characteristics. The cylindrical specimens were prepared from longitudinal and transverse direction, respectively. Impact tests were performed under different strain rates of 103 s-1, 2×103 s-1, 3×103 s-1 and 5×103 s-1 at room temperature for transverse specimens and at both room temperature and high temperature of 350ºC for longitudinal specimens.
The results reveal that the mechanical properties and microstructures of the current alloy are greatly affected by directional grain structures, temperature and strain rates. It is found that the flow stresses and strain rate sensitivity increase with increasing strain rate. However, the activation volume decreases as the strain rate is increased. The flow behavior in high temperature conditions exhibits a lower work hardening rate, and a higher strain rate sensitivity. This result indicates a pronounced work hardening effect is appeared in high temperature as high strain rate loading is imposed. Finally, the Zerilli-Armstrong model is shown to provide an adequate description of the stress-strain response of 7075-T6 specimens under the considered grain direction, strain rate and temperature. Furthermore, according to the microscopic results, the relationship between the dislocation density, dislocation cells and grain size can be expressed using the modified Hall-Petch equation.

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