本實驗主要是將AC8A鋁矽合金在不同的擠製路徑A、Bc及C，以模角120°、外側弧角為0°及擠製溫度為200℃及275℃進行ECAE擠製，並且在不同的道次(4道及8道)下，以拉伸試驗觀察擠製路徑對延展性的影響。
AC8A鋁矽合金在不同的擠製路徑A、Bc及C進行200℃擠製4道，以拉伸試驗觀察伸長量發現擠製路徑對伸長量無明顯的影響，但在擠製溫度為275℃以路徑A擠製4道後，明顯發現擠製溫度越高，伸長量越高，而在擠製溫度為275℃以路徑A擠製8道後，伸長量也明顯隨著道次的增加而增加。而藉由拉伸測試所得到的最大拉伸強度中得知不管擠製路徑為何，對最大拉伸強度的影響並無差異。

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目錄
圖表目錄 IV一、前言 1
二、文獻回顧 3
2-1 AC8A 鋁矽合金 3
2-1-1 AC8A鋁矽合金之介紹 3
2-1-2 AC8A鋁矽合金之熱處理 3
2-1-3 AC8A鋁矽合金之機械性質及微結構 7
2-2大量塑性變形及晶粒細化 9
2-3等徑轉角擠型(Equal Channel Angular Extrusion,ECAE) 10
2-3-1等徑轉角擠型之原理 10
2-3-2等徑轉角擠型之優點 10
2-4影響ECAE變形的參數 11
2-4-1模角(die angle) 11
2-4-2擠製路徑的影響 12
2-4-3擠製溫度的影響 14
2-5超細晶金屬之機械性質 16
2-5-1 Hall-Petch關係式 16
2-5-2超細晶粒的Hall-Petch關係式解釋 17
三、研究目的 19
四、實驗方法 20
4-1材料和實驗設備 20
4-2等徑轉角擠製之試棒製作 21
4-3金相觀察 22
4-4 SEM分析 22
4-5 微硬度測試 23
4-6 拉伸的機械性質測試 23
4-7變形試片的破斷面觀察 23
4-8 TEM分析 24
五、實驗結果 26
5-1金相觀察 26
5-1-1擠製溫度對微結構的影響 27
5-1-2擠製路徑對微結構的影響 27
5-2 SEM觀察 28
5-2-1 SEM觀察Al晶粒大小 28
5-2-2 SEM觀察Si晶粒大小 29
5-3微硬度測試 30
5-3-1溫度效應 30
5-3-2擠製道次對硬度的影響 32
5-4 拉伸測試 32
5-4-1 擠製路徑對拉伸測試的影響 32
5-4-2 擠製道次對拉伸測試的影響 34
5-4-3 擠製溫度對拉伸測試的影響 34
5-4-4熱處理對拉伸測試的影響 35
5-5 TEM結果 36
六、討論 38
6-1等徑轉角擠型擠製參數的影響 38
6-2 熱處理的影響 40
七、結論 42
八、參考文獻 44

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