本研究利用實驗測量和理論預測水往上結冰且含有氧氣和二氧化碳時氣泡在固液界前成核後的氣泡尺寸;冷卻溫度-25 , -15 C測量氣泡形狀,顯示氣孔形成可分為五部份,包括(1)固液界面之成核(2)氣泡頂端之成長(3)固化速度所控制之氣泡成長(4)氣泡之消失(5)固體內形成氣孔;解釋實驗結果時,方程式包含氣泡頂端成長率和固化速度成功預測氣泡頂端成長和固化速度所控制之氣泡成長區固體內的氣泡形狀;實驗數據顯示初始氣體濃度和固化速度對固體內氣泡幾何形狀的影響。

The sizes of a bubble trapped in solid after nucleation on the solidification front during an upward freezing of water containing a dissolved oxygen or carbon dioxide gas are experimentally measured and quantitatively predicted in this work. From an in situ measurements of bubble shapes in solid at cold temperatures of -25 and -15 C, it quantitatively shows that pore formation can be divided into five regimes: (1) nucleation on the solidification front, (2) spherical growth, (3) solidification rate-controlled elongation, (4) disappearance of the bubbles, and (5) formation of the pores in solid. To interpret experimental results, equations incorporated with the growth rate of a spherical bubble and solidification rate to predict bubble shapes in the solid during the spherical growth and solidification rate-controlled elongation are successfully proposed. Experimental data show the effects of initial gas concentration and solidification rate on geometries of the bubble in solid.

中文摘要 i

Abstract ii

圖目錄 iii

符號說明 v

第一章 緒論 1
1-1 文獻回顧 1
1-2 研究目的 4

第二章 系統模型 5
2-1 理論分析 6
2-2 數值分析 8

第三章 實驗設定 10

第四章 結果與討論 11
4-1 固化位置、溫度和溶質氣體濃度 11
4-2 在固體內氣泡的形狀 17
4-3 測量值和預測值的比較 21
4-4 在固體內氣泡形狀的其它結果 23

第五章 結論 29

附錄一 30

附錄二 31

參考文獻 33

[1]S. Kou, Welding Metallurgy. Wiley, New York, 1987.
[2]M. C. Flemings, Solidification Processing, McGraw-Hill, New York, 1974.
[3]J. E. Ramirez, B. Han, S. Liu, Metall. Mater. Trans. 25A (1994) 2285.
[4]K. Nogi, Y. Aoki, H. Fujii, K. Nakata, Acta Mater. 46 (1998) 4405.
[5]K. A. Jackson, J. D. Hunt, Acta Metallurgica 13 (1965) 1212.
[6]C. C. Huang. Bubble/pore shapes in solid during solidification, Master thesis, Department Mechanical and Electro-Mechanical Engineering., National Sun Yat-Sen University, 2003.
[7]P. S. Wei, C. C. Huang, K. W. Lee, Metall. Mater. Trans. 34B (2003) 321.
[8]K. Murakami, H. Nakajima: Mater. Trans. 43 (2002) 2582.
[9]P. S. Wei, Y. K. Kuo, S. H. Chiu, C. Y. Ho, Int. J. Heat Mass Transfer 43(2000)263.
[10]P. S. Wei, C. Y. Ho, Metall. Mater. Trans. 33B (2002) 91.
[11]M. V. A. Bianchi, R. Viskanta, Int. J. Heat Mass Transfer 42(1999)1097.
[12] R. Mehrabian, Int. Metals Reviews 27(1982)185.
[13]T. W. Clyne, Metall.Trans. 15B(1984) 369.
[14]F. B. Yeh, P. S. Wei, S. H. Chiu, J. Crystal Growth 247(2003) 563.
[15]P. S. Wei, F. B. Yeh, J. Heat Transfer 122(2000) 792.
[16]M. V. A. Bianchi, R. Viskanta, Int. J. Heat Mass Transfer 40(1997) 2035.
[17]L. S. Ettre, J. Chromatographic Sci. 36(1998) 322.
[18]P. S. Epstein, M. S. Plesset, J. Chem. Phys. 18(1950) 1505.
[19]L. E. Scriven, Chem. Eng. Sci. 10(1959) 1.
[20]D. E. Rosner, M. Epstein, Chem. Eng. Sci. 27(1972) 69.
[21]P. Payvar, Int. J. Heat Mass Transfer 30(1987) 699.
[22]H. Y. Kwak, Y. W. Kim, Int. J. Heat Mass Transfer 41(1998)757.
[23]R. Viskanta, 50th Anniversary Issue, J. Heat Transfer 110(1988)1205.
[24]J. T. Davies, E. K. Rideal. Interfacial Phenomena, 2nd edition, Academic Press, New York, 1963, Chapter 7.
[25]W. K. Lewis, W. G. Whitman, Industrial and Engineering Chemistry 16(1924)1215.
[26]R. Higbie, Trans. AIChE 31(1935)365.
[27]D. Papamantellos, K. W. Lange, K. Okohira, H. Schenck, Metall. Trans. 2(1971)3135.
[28]G. H. Geiger, D. R. Poirier. Transport Phenomena in Metallurgy, Addison-Wesley, Reading, Massachusetts; 1973, p. 463-468.