臺灣博碩士論文加值系統

鑄態鎂鋁合金鑄件微結構的研究與發展，取決於鑄造人員的知識與能力，目前關於鎂合金鑄態凝固過程和其微結構的完整資料較少，因此，本研究的目標係建立鎂鋁合金於凝固過程的製程參數與描繪相關之微結構。
本研究主要利用CA-CCA(computer aided – cooling curve analysis)與金相量化分析(quantitative metallography analysis)探討鎂鋁合金於凝固過程之行為，使用的材料有商用鎂鋁合金AZ91與本實驗利用純鎂(3N)與純鋁(3N)調配之鎂鋁合金：Mg-3Al, Mg-6Al, Mg-9Al and Mg-15Al，微結構則使用光學顯微鏡、掃描式電子顯微鏡與EDS line scan 觀察與辨別各種不同析出相的形態與成分。
本實驗的冷卻速率範圍約為10-40 ，冷卻速率提高使得鎂鋁合金之鋁的固溶度降低，造成二次相(Mg17Al12)析出比率減少，金相量化分析顯示冷卻速率越快而析出物尺寸與析出比率越低，金相量化分析也可定義二次相(Mg17Al12)存在的臨界尺寸。藉此研究應可提供未來鑄態鎂鋁合金相關之製程參數與參考資料庫。

Research and development of magnesium casting alloy depends largely on the metallurgist’s understanding and ability to control the microstructure of the as-cast part. Currently few sources of magnesium solidification information and as-cast microstructure exist. Therefore, the purpose of this research is to create the general database of magnesium solidification behavior and to characterize the resultant microstructures.
Experiment has been development and constructed to study the solidification behavior of magnesium-aluminum alloy casting alloys via CA-CCA(computer aided – cooling curve analysis) and quantitative metallography analysis. These analyses have been performed on five kinds of magnesium-aluminum alloys, including commercial AZ91 magnesium alloy, and experimental alloys which was mixed with pure magnesium (3N) and pure aluminum (3N) such as Mg-3Al, Mg-6Al, Mg-9Al and Mg-15Al. The resultant microstructure has been characterized for microstructures and the various phases were analyzed using optical and scanning electron microscopy, as well as energy dispersive x-ray spectroscopy.
The measurement were performed using a cooling rate on the order 10-40 , and results of these analyses show the higher cooling rate, the lower volume fraction of Mg17Al12 precipitation, and this is because the solid solution of Al in Mg-Al is controlled by cooling rate. Quantitative metallography analysis reveals the relationship between cooling rate and as-cast microstructure. It also can be used to define critical conditions for existing partially divorced and fully divorced precipitation. Finally, these results should provide useful knowledge for research towards develop casting procedure of magnesium alloys.

目錄
中文摘要 I
英文摘要 II
圖目錄 V
表目錄 VII
一、 前言 1
二、 文獻回顧 2
2-1 鎂合金的應用與發展 2
2-1-1 金屬冶煉 2
2-1-2 構造用材料 2
2-2 鎂合金材料的介紹 5
2-2-1 鎂金屬的性質 5
2-2-1-1 原子性質 5
2-2-1-2 結晶結構 5
2-2-1-3 滑移系統 6
2-2-1-4 物理性質 6
2-2-1-5 熱力性質 7
2-2-2 鎂合金 7
2-2-3 鎂合金的分類 10
2-2-4 鎂合金添加合金元素的影響 12
2-2-5 鎂鋁合金添加稀土元素的影響 13
2-3 鎂資源 16
三、 理論探討 17
3-1 鎂鋁合金的凝固 17
3-1-1 鎂合金晶粒的成長機制 17
3-1-2 鎂鋁合金的共晶結構 21
3-1-3 鎂鋁合金微結構中之介在物 22
3-1-4 冷卻速率對鎂合金凝固之影響 23
3-2 鎂合金的熱處理 23
3-2-1 熱處理 23
3-2-2 影響熱處理的主要因素 24
3-2-3 合金熱處理之保護氣氛 25
3-2-4 鎂合金之固溶後效處理（T6 treatment） 25
3-2-4-1 固溶處理（solution treatment） 25
3-2-4-2 時效處理（aging treatment） 28
3-3 熱分析法的介紹 33
3-3-1 熱分析法原理 33
3-3-2 熱分析法衍生的理論基礎 33
3-3-3 CA-CCA的理論 34
四、 實驗方法與步驟 38
4-1 實驗材料 38
4-2 實驗設計 39
4-3 實驗設備 40
4-3-1 熔煉設備 40
4-3-2 保護性氣體 40
4-3-3 資料擷取系統 40
4-3-4 掃描式電子顯微鏡（SEM） 40
4-3-5 電子微探儀（EPMA） 41
4-4 實驗步驟 42
4-4-1 熔煉作業 42
4-4-2 金相觀察 43
4-4-3 微結構影像分析 44
五、 實驗結果與討論 45
5-1 成分分析 45
5-2 鎂鋁合金之熱分析 46
5-2-1 AZ91D冷卻曲線分析 46
5-2-2 AZ91D凝固過程之固相分率變化 48
5-2-3 Mg-9Al凝固過程之固相分率變化 53
5-3 鎂鋁合金之微結構分析 57
5-4 鎂鋁合金微結構之金相量化分析 61
5-4-1 形狀因子 61
5-4-2 不同鋁含量與冷卻速率對於鎂鋁合金微結構之影響 63
六、結論 75
參考文獻 76

參考文獻
[1]Courtesy of international magnesium association, 1997
[2]「車?重量別燃料及CO２排出?況」, 國土交通省, 日本
[3]Michael M. Anderson, ASM specialty handbook/magnesium and magnesium alloys, 1999
[4]Hisao Watarai,” Trend of research and development for magnesium alloys”, Science and Technology Trends/Quarterly Review, 18, 2006
[5]G. V. Raynor, The physical metallurgy of magnesium and it’s alloys, p. 103, 1959
[6]Nobert Hort, “Intermetallics in magnesium alloys” Advanced Engineering Materials, 2006
[7]ASM, Metals Handbook, 10th ed., V9
[8]Matthew S. Dargusch, “The effect of aluminum content on the mechanical properties and microstructure of die cast binary magnesium aluminum alloys”, Materials Transactions, V47, N4,pp. 977-982 , 2006
[9]Mordike BL, Magnesium alloys and their applications DGM information, Germany, p. 111
[10]Sun YS, Acta Metall Sin , 4 , p. 253, 2001
[11]孔志剛, 「Zr含量對Mg-Zr合金組織和性能的影響」, 北京航空大學學報, 20, 2004
[12]Xue Feng, “Microstructure and mechanical properties of AZ91 alloys with combined additions of Ca and Si”, Journal of Material Science, pp. 4725-4731, 2006
[13]M. Qian, Scripta Materialia, 52, pp. 415-419, 2005
[14]Yeshuang Wang, ”Effect of Zn and RE additions on the solidification behavior of Mg-9Al magnesium alloy”, Materials Science and Engineering A, 342, pp. 178-182, 2003
[15]Jingli Yan, “Microstructure and mechanical properties in cast magnesium-neodymium binary alloy”, Materials Science and Engineering A, 476, pp. 366-371, 2008
[16]X. Tian, “The microstructure and mechanical properties of Mg-3Al-RE alloys”, Journal of Alloys and Compounds, 2007
[17]Wang MinXian, “Effects of yttrium and cerium addition on the microstructure and mechanical properties of AM50 magnesium alloy”, Journal of Rare Earth, 25, pp. 233-257, 2007
[18]Yizhen Lu, “Effects of rare earth on the microstructure, properties and fracture behavior of Mg-Al alloys”, Materials Science and Engineering A, 278, pp. 66-76, 2000
[19]XIE Jian-Chang, “Microstructure and mechanical properties of AZ81 magnesium alloy with Y and Nd elements, Transactions of Nonferrous Metals Society of China, 18, pp. 303-308, 2008
[20]Guohua Wu, “The effect of Ca and rare earth elements on the microstructure and mechanical properties and corrosion behavior of AZ91D”, Materials Science and Engineering A, 408, pp. 255-263, 2005
[21]中國有色金屬工業協會, 海峽兩岸及香港鎂產業, p. 12, 2005
[22]A.K. Dahle, Mater. Forum, 24, 2000, pp. 167-182
[23]H. L. Su, “Experimental investigation of Mg-Al phase diagram from 47 to 63 at.% Al”, Journal of alloys and compounds, 1997
[24]Alloy Phase Diagrams, ASM Handbook Committee, 1992
[25]E. Aghion, ”Physical metallurgy of magnesium alloy ingots and die castings”, Magnesium alloys and their applications, p. 295, 1998
[26]Robert E. Reed – Hill, Physical Metallurgy Principles, 3rd , 1992
[27]鄭偉超, 「Mg - Al二元合金組織和性能的研究」, 鑄造, V55, N1, p15-19, 2006
[28]E. M. , “Influence of technological parameters of permanent mold casting and die casting on creep and strength of Mg alloy AZ91D ”, Material Science Engineering A, 234, pp. 880-883, 1997
[29]A.K. Dahle, “Development of the as-cast microstructure in magnesium-aluminum alloys”, Journal of Light Metal, pp. 61-72 , 2006
[30]Adebayo Badmas, ”Impulse atomized and ingot chip magnesium alloy: microstructure comparison” , The International Journal of Powder Metallurgy, V39, No2, 2003
[31]Yosuke Tamura, “Observation of manganese-bearing particles in molten AZ91 magnesium alloy by rapid solidification”, Materials Transaction, Vol.44, 2003
[32]R. M. Wang, “Microstructure and dislocations in the stressed AZ91D magnesium alloys”, Materials Science and Engineering A, 344, pp. 279-287, 2002
[33]S. Lun Sin, ”Characterization of Al-Mn particles in AZ91D investment castings”, Material Characterization, 58, pp. 989-996, 2007
[34]R. M. Wang, “An investigation on the microstructure of an AM50 magnesium alloy”, Materials Science and Engineering A, 355, pp. 201-207, 2003
[35]S. Barbagallo, “Divorced eutectic in a HPDC magnesium-aluminum alloy”, Journal of Alloys and Compounds, 378, pp. 226-232, 2004
[36]Chi-Yuan Cho, “Effect of cooling rate on Mg17Al12 volume fraction and compositional inhomogenneity in a sand-cast AZ91D magnesium plate”, Materials Transactions, 47, No.8, pp. 2060-2067, 2006
[37]“Heat treating of nonferrous alloys”, ASM Handbook, Vol. 4, 1991
[38]Kaya A.A, “Electron microscopical investigation of as-cast AZ91D”, Material Science Technology, 9, p1001, 2000
[39]Wang Y, “Microstructure evolution of rheo-diecast AZ91D magnesium alloy during heat treatment”, Acta Materialia, 54, p. 689, 2006
[40]Y. Tamura, “The effect of manganese on the precipitation of Mg17Al12 phase in magnesium alloy AZ91”, Journal of Materials Science, 2007
[41]田村洋介, 「AZ91合金時效析出舉動機械的性質及影響」, 輕金屬, 第57卷, 第10?, pp. 450–456, 2007
[42]Clark JB, ”Age hardening in a Mg-9wt.% Al alloy” , Acta Metallurgica, 16, 1968
[43]M. X. Zhang, ”Crystallography of Mg17Al12 precipitates in AZ91D alloy”, Scripta Materialia, 47, pp. 647-652, 2003
[44]Duly D, ”On the competition between continuous and discontinuous precipitation in binary Mg-Al alloys” , Acta Metall Mater, 43, pp. 101-106 , 1995
[45]D. Duly, “Nucleation mechanism of discontinuous precipitation in Mg-Al alloys and relation with the morphology”, Acta Metallurgica et Materialia, 42, No.9, pp. 3035-3043, 1994
[46]D. Duly, “Morphology and mechanical nanoanalysis of discontinuous precipitation in Mg-Al alloys – I. regular growth”, Acta Metallurgica et Materialia, 42, No.11, pp. 3843-3854, 1994
[47]D. Duly, “Morphology and mechanical nanoanalysis of discontinuous precipitation in Mg-Al alloys – II. irregular growth”, Acta Metallurgica et Materialia , 42, No.11, pp. 3855-3863, 1994
[48]石川圭介, 「AZ91D合金析出性質機械的性質」, 日本金屬學會誌, 第61卷, 第10?, 1997, pp. 1031-1036
[49]高飛鳶, 「不同鑄造參數及斷面模數之鑄件凝固分析」, 中央大學, 1992
[50]K.G. Upadhya, Principles and application in metal casting, Vol.97, pp. 61-66, 1989
[51]I.G. Chen, AFS Transactions, Vol.92, pp. 947-964, 1984
[52]黃文星, 「Sn-9Zn-xAg無鉛銲錫合金熱物性質與凝固特性之實驗量測與數值分析」, 行政院國家科學委員會專題計畫研究成果報告, 2001
[53]A. Lindemann, “Thermal analytical investigation of the magnesium alloys AM60 and AZ91 including melting range”, Thermochimica Acta, 382, pp. 269-275, 2002
[54]Kojima T., “Circularity ratio, a certain quantitative expression fir the circularity of a round figure”, Okajimas Folia Anatomica Japonica, 48, pp. 153-161, 1971