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研究生:洪佩菁
研究生(外文):Pei-Ching Hung
論文名稱:次微米晶粒鋁之拉伸變形行為
論文名稱(外文):The tensile properties of sub-micron Al
指導教授:高伯威
指導教授(外文):Po-We Kao
學位類別:碩士
校院名稱:國立中山大學
系所名稱:材料科學研究所
學門:工程學門
學類:材料工程學類
論文種類:學術論文
論文出版年:2004
畢業學年度:92
語文別:中文
論文頁數:84
中文關鍵詞:擴散頸縮局部化頸縮剪變形帶
外文關鍵詞:localized neckingdiffuse neckingShear band
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本實驗利用等徑轉角擠型(ECAE)以路徑BC擠製來製造細晶粒鋁,並利用不同的退火條件來取得晶粒尺寸在0.4�慆~1�慆範圍,並對材料在室溫以及77K溫度下進行拉伸試驗。實驗結果顯示,當應力-應變曲線出現降伏下降時,試片表面也會伴隨著出現剪變形帶;而且在不同的拉伸溫度下,其拉伸變形行為很有很大的變化。
此外實驗中也以路徑C分別擠製2、4、6、8及9道,並進行拉伸試驗,結果發現以路徑BC擠製所測得的結果,要比以路徑C擠製所測得的結果要來的好;而且兩種不同的擠製路徑,其拉伸表面的變形現象也十分的不同;尤其在低溫拉伸時兩者之間的差異更大。
而實驗結果也發現利用改變擠製道數對於拉伸性質並不會造成很大的影響,無論在室溫或是77K溫度拉伸,其表面變形行為也僅有些許的變化。
In this experimental, we use ECAE with route BC to produce the ultrafine-grain Al and use different annealing temperature to get grain size at 0.4�慆 ~ 1�n�慆. Then materials process the tensile test at room temperature and 77K. By our result, we find that when stress-strain curve occur a yield drop, at the same time, we can see a shear band appear at the surface of the tensile specimen. Besides, at different tensile temperature, we find different tensile properties.
On the other hand, we also use ECAE with route C to extrude 2, 4, 6, 8 and 9 passes, and then processed the tensile test. According the result, we can know that materials extruded by route BC have higher tensile strength than materials extruded by route C. But we find wherever test at RT or 77K, different extrude passes their tensile properties only have slightly changes.
圖表目錄………………………………………………………………………………I
一、前言………………………………………………………………………………1
二、文獻回顧…………………………………………………………………………3
2.1 Hall-Petch 關係式……………………………………………………………… 3
2.1.1超細晶粒的Hall-Petch關係式解釋……………………………………… 4
2-2 降伏現象………………………………………………………………………..4
2-3 路德氏變形…………………………………………………………………… 5
2-4 剪切變形………………………………………………………………………..6
2-5 超細晶金屬的加工硬化行為…………………………………………………..8
2-6 利用等徑轉角擠型製造超細晶粒材料………………………………………..8
2-7 熱處理………………………………………………………………………….10
三、研究目的 12
四、實驗方法 13
4.1 實驗用材料.........................................................................................................13
4-2 退火處理條件………………………………………………………………….13
4-3 拉伸試驗……………………………………………………………………….13
4-4 變形試片的表面觀察………………………………………………………….14
4-5 微結構分析…………………………………………………………………….14
五、實驗結果 15
5-1 經路徑BC擠製8道之拉伸性質.. ………………………………………..15
5-1-1 室溫下拉伸試驗 15
5-1-2 77K下拉伸試驗 15
5-2經路徑C擠製不同道數之拉伸性質…………………………………….. …..15
5-2-1 室溫下拉伸試驗 16
5-2-2 77K下拉伸試驗 16
5-3 不同擠製路徑相同退火條件之拉伸性質……………………………….........17
5-3-1 室溫下拉伸試驗 17
5-3-2 77K拉伸試驗 17
5-4以路徑BC擠製經拉伸試驗之表面變形現象…………………………………18
5-4-1 室溫拉伸後之表面變形 18
5-4-2 77K拉伸後之表面變形 20
5-5以路徑C擠製經拉伸試驗之表面變形現象 ……………………………..22
5-5-1 室溫拉伸後之表面變形 22
5-5-2 77K拉伸後之表面變形 25
六、討論 27
6-1 變形行為…...…………………………………………………………………. 27
6-2 變形與降伏關係……………………………………………………………… 28
6-3 以不同擠製路徑對拉伸性質的影響………………………………………… 30
6-4 相同擠製路徑、不同擠製道數之影響……………………………………… 31
七、結論 32
八、參考文獻……………………………………………………………………......34
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庾忠義,中山大學博士論文 (2003)

孫佩鈴,中山大學博士論文 (2002)
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