鎂合金因為材料比強度高、密度低、減震性、電磁屏蔽性及導熱性良好常被使用在電子資訊3C產品或航太等等工業領域中，為了使產品能有更優良的機械性質，本研究採用熱間塑性變形的方式使材料產生動態再結晶粒，使晶粒細化從而達到增加產品強度的目的。本研究透過壓縮試驗所得出的材料塑流應力中，得出材料剛開始發生動態再結晶時之臨界應變及50%動態再結晶時之應變等資料，並透過數學回歸方法，建構出鎂合金ZK60的再結晶預測式。最後使用有限元素軟體DEFORM-2D，以預測出鎂合金ZK60熱間壓延中產生的動態再結晶行為及不同壓延製程條件對動態再結晶的影響，本研究模擬結果顯示，輥軋溫度400 ℃和壓下率40% 為最佳模擬條件，可以得到平均晶粒尺寸為0.55 μm ~ 1.37 μm細小且均勻的晶粒組織，鎂合強度和成形性將可以得到改善。
本研究最後會進行單道次以及多道次熱間壓延實驗，並改變不同的製程條件如：溫度、壓下率及討論輥輪加熱前後之差異等等，並以金相觀察其微觀組織，比較ZK60鎂合金在不同製程條件下的再結晶程度及晶粒尺寸，以及做一系列的機械性質探討，並驗證模擬解析之妥當性。實驗結果中，板材溫度400 ℃的高溫會導致壓延後的晶粒因快速的成長而對平均晶粒結果產生較大的誤差，而溫度300 ℃的平均晶粒量測結果誤差約為30%。

Magnesium alloys have various characteristics, such as high strength, low density, strong shock absorption ability, electromagnetic shielding and good thermal conductivity. They are widely applied in electronic products and aerospace industries. In this study, in order to make the product have better mechanical properties, using dynamic recrystallization (DRX) to make grain refinement to increase the strength of the product by applying plastic deformation in hot-working. The flow stress of Magnesium alloy ZK60 can be obtained by compression test. The peak of the flow stress, including peak stress and peak strain, and the strain of 50% DRX strain can be applied in DRX prediction equation by using mathematical regression method. After the DRX prediction equation is done, key in FEM software DEFORM-2D to predict the effects of magnesium alloy ZK60 dynamic recrystallization behavior in hot-rolling and rolling process conditions. The simulation results show that a rolling temperature of 400 ℃ and a thickness reduction of 40% are the optimal conditions. An average grain size of 0.55 μm- 1.37 μm in the microstructure is obtained and the strength and formability of ZK60 magnesium alloys is improved.
Finally, this study has made one pass and multi-pass hot-rolling experiment by changing different process conditions, such as, temperature, pressure ratio and roll temperature, etc.. After the metallographic microstructure observation, comparison under the same process conditions degree of recrystallization and grain size, as well as do a series of mechanical properties are discussed and resolved to verify the correctness of the simulation. The experimental results show the average grain size of sheet temperature of 400 ℃ after rolling have large errors, because the grain growing rate is too fast. The error of the measurement result of average grain size at 300 ℃ is about 30%.

目錄
致謝 i
摘要 ii
Abstract iii
圖目錄 vii
表目錄 xi
符號說明 xii
第一章 緒論 1
1-1 前言 1
1-2 鎂合金的特色與熱軋產品之應用 2
1-2-1 添加各種合金元素對鎂合金之影響 4
1-3 金屬強化種類簡介 6
1-3-1 固溶強化 6
1-3-2 析出硬化 6
1-3-3 加工強化 7
1-3-4 相變化 7
1-3-5 晶粒細化 8
1-4文獻回顧 8
1-4-1 鎂合金或其他金屬壓延之相關文獻 8
1-4-2 動態再結晶之相關文獻 10
1-4-3 多道次壓延之相關文獻 11
1-5 研究目的與本文架構 11
第二章 熱間壓延之有限元素解析 13
2-1 有限元素解析 13
2-1-1 有限元素解析軟體DEFORM介紹 13
2-2 壓縮試驗之規格及壓縮規劃 14
2-2-1 塑流應力之求得 16
2-3 動態再結晶模式之建立 17
2-4 變形活化能及再結晶預測式係數之推導 20
2-4-1 塑流應力本構方程式 20
2-4-2 變形活化能 21
2-4-3 動態再結晶體積百分比 23
2-4-4 臨界應變 24
2-4-5 50%動態再結晶之應變 26
2-4-6 動態再結晶晶粒尺寸 27
2-5 鎂合金板熱間壓延的有限元素模式之建立 28
2-5-1 熱間壓延模擬之基本假設 28
2-5-2 有限元素模擬步驟 29
2-5-3 板材網格之收斂性分析 29
2-5-4 熱間壓延模擬參數之建立 31
第三章 鎂合金之熱間壓延實驗 33
3-1 前言 33
3-2 單道次熱間壓延實驗 35
3-2-1 壓延機規格說明 35
3-2-2 荷重計之校正 36
3-2-3 輥輪加熱設備 37
3-2-4 單道次壓延實驗之規劃與步驟 39
3-3 多道次壓延之實驗 41
3-4 板材壓延前後之金相觀察 42
第四章 解析與實驗結果之討論 47
4-1 鎂合金模擬解析結果 47
4-1-1 輥輪有無加熱對板材溫度歷程之影響 47
4-1-2輥輪有無加熱對壓延力之影響 53
4-1-3 動態再結晶模擬結果 54
4-1-4 總結各種壓延參數對模擬結果之影響 68
4-2 鎂合金單道次壓延實驗結果 69
4-2-1 輥輪有無加熱對產品之外觀比較 69
4-2-2 輥輪有無加熱對壓延力及壓下率之影響 70
4-3 解析結果與實驗結果之比較 72
4-4 板材壓延前後之單軸拉伸試驗結果 75
4-5 鎂合金多道次壓延實驗結果 79
4-5-1 各道次對晶粒尺寸的影響 79
4-5-2 各道次之單軸拉伸試驗結果 81
第五章 結論與未來展望 83
5-1 鎂合金熱間壓延有限元素解析 83
5-2 鎂合金熱間壓延實驗 84
5-2-1 鎂合金單道次壓延 84
5-2-2 鎂合金多道次壓延 85
5-3 未來展望 85
參考文獻 86

參考文獻
[1] 王建義, 鄭達謙, “不同壓延製程控制顯微組織對ZK60鎂合金高溫機械性質影響之研究”, 國立東華大學材料科學與工程研究所碩士論文, pp.18 (2010)
[2] Y. Chino, X. Huang, K. Mabuchi, “Enhancement of Stretch Formability at Room Temperature by Addition of Ca in Mg-Zn Alloy”, Master. Trans., Vol 51, pp.818-821 (2010)
[3] http://ccmg.cqu.edu.cn/?idx=page&act=show&id=18
[4] 黃永茂, 陳炫翰, “鎂合金AZ31熱間壓延之相關研究”, 國立中山大學機械與機電工程研究所碩士論文,pp.3-7 (2014)
[5] 井上 忠信, “塑性加工による超微細粒金属材料の先進的研究”, Journal of the JSTP, vol. 55, no. 647 (2014)
[6] 薛克敏, 張君, 李萍, 黄科帥, “高壓扭轉法的研究現況及展望”, 合肥工業大學材料科學與工程學院.
[7] Nobuhiro, Yoshihiro, S.H. Lee, Yoritoshi, “ARB(Accumulative Roll-Bonding) and Other New Techniques to Produce Bulk Ultrafine Grained Materials”, Advanced Engineering Materials, 5, No.5, (2003)
[8] 野田 雅史, 森 久史, 船見 国男, 権田 善史, “難燃性Mg - 10Al - 1Ca合金中板材の圧延加工による機械的特性の向上と組織”, 塑性加工春季講演会, (2014)
[9] K. Yu, X.Y. Wang, Z.Y. Cai, R.C. Wang, D. Shi, “Finite Element Simulation of Deformation in Hot Rolling Process of AZ31 Magnesium Alloy”, Journal of Central South University, Vol.40, No.6, Dec. (2009)
[10] 杉井 秀夫, 加藤 雅之, 松本 貢一, 津田 康宏, “マグネシウム合金の熱間圧延におけるロールコーティングと潤滑性”, 塑性加工春季講演会, (2009)
[11] 真鍋 翔, 宇都宮 裕, 松本 良, 服部 雅弘, 左海 哲夫, “圧延によるマグネシウム合金AZ31板に発生する緣割裂れの型態”, 塑性加工春季講演会, (2012)
[12] 橋本 旭令, 浜田 剛, 渡部 洋平, 左海 哲夫, 宇都宮 裕, “AZ91マグネシウム合金板の冷温間域高速圧延”, 塑性加工春季講演会, (2009)
[13] C.X. Yue, L.W. Zhang, J.H. Ruan, H.J. Gao, “Modelling of Recrystallization Behavior and Austenite Grain Size Evolution During the Hot Rolling of GCr15 Rod”, Applied Mathematical Modelling 34, pp.2644–2653. (2010)
[14] M. Toloui, S. Serajzadeh, “Microstructural Evolution on Streamlines During Hot Strip Rolling Using Internal State Variables”, journal of materials processing technology, 209, pp.1717–1728. (2009)
[15] H.F. Sun, S.J. Liang, E.D. Wang, “Mechanical Properties and Texture Evolution During Hot Rolling of AZ31 Magnesium Alloy”, Trans. Nonferrous Met. Soc. China, 19, s349-s354, (2009)
[16] Y.Z. Wu, H.G. Yan, S.Q. Zhu, J.H. Chen, A.M. Liu, X.L. Liu, “Flow Behavior and Microstructure of ZK60 Magnesium Alloy Compression at High Strain Rate”, T. Nonferrous Met. Soc. China 24, pp. 930-939. (2014)
[17] B.L. Shi, T.J. Wang, J.Wang, Y.S. Yang, “Hot Compression Behavior and Deformation Microstructure of Mg- 6Zn- 1Al- 0.3Mn”, T. Nonferrous Met. Soc. China 23, 2560-2567. (2013)
[18] E.E.V. Dupin, M. Soltanpour, 柳田 明, 柳本 潤, “Quantification of the Kinetics of Microstructure Evolution Under Hot Forming of SUS 316 Strainless steel”, 第63回塑性加工聯合講演会, (2012)
[19] 野田雅史, 船見 国男, 岡田 真人, “AZ31マグネシウム合金圧延材の成形性に及ぼす微視組織の影響”, 日本機械学会論文集 (A編), Vol.78, No.789 (2012)
[20] H.L. Guo, Z.C. Sun, H. Yang, “Empirical Recrystallization Model and Its Application of Asextruded Aluminum Alloy 7075”, The Chinese Journal of Nonferrous Metals, Vol.23, No.6, (2013)
[21] H.L. Ding, Kanamori, Honma, Kamado, Kojima, “ FEM Analysis for Hot Rolling Process of AM60 Alloy”, Trans. Nonferrous Met. Soc. China 18, s242−s246 (2008)
[22] Yorinobu, Masayoshi, Tokuteru, Kenji, “Effect of Initial Grain Size on Dynamically Recrystallized Grain Size in AZ31 Magnesium Alloy”, Materials Transactions, Vol. 49, No. 9, pp.1979 –1982, (2008)
[23] H. Zhang, G.S. Huang, L.F. Wang, Hans Jørgen Roven, F.S. Pan, “Enhanced mechanical properties of AZ31 magnesium alloy sheets processed by three-directional rolling”, Journal of Alloys and Compounds 575, pp.408–413, (2013)
[24] X. Wang, C. Yang, L. X. Hu, “Mechanical Properties and Isothermal Rolling Process of AZ31 As-cast Mg alloy Plate”, Materials Science and Technology, Vol 19, No.2 , ( 2011)
[25] H.L. Ding, T.Y. Wang, L. Yang, Shigeharu, “FEM Modeling of Dynamical Recrystallization During Multi-pass Hot Rolling of AM50 Alloy and Experimental Verification”, Trans. Nonferrous Met. Soc. China 23, pp.2678−2685 (2013)
[26] 福島 傑浩, 脇田 昌幸, 江藤 学, 柳田 明, 柳本 潤, “極短パス間時間多パス圧延プロセスによる微細結晶粒生成の予測技術”, 第64回塑性加工聯合講演会, (2013)
[27] F.L. Sui, Y. Zuo, X.H. Liu, L.Q. Chen, “Microstructure Analysis on IN 718 Alloy Round Rod by FEM in the Hot Continuous Rolling Process”, Applied Mathematical Modelling 37, pp.8776–8784. (2013)
[28] M.T. Wang, X.L. Zang, X.T. Li, F.S. Du, “Finite Element Simulation of Hot Strip Continuous Rolling Process Coupling Microstructural Evolution”, Journal of Iron and Steel Research, International,14 (3) : pp.30-36, (2007)
[29] Y. S. Yang, D. C. Ko, B. M. Kim, ”Application of the Finite Element Method to Predict Microstructure Evolution in the Hot Forging of Steel”, Journal of Materials Processing Technology, 101(1/3): pp. 85−94 (2000)
[30] C.M. Sellars, “Basics of Modelling for Control of Microstructure in Thermomechanical Control Processing”, Ironmaking and Steelmaking, 22, 459–464 (1995)
[31] T. Senuma, H. Yada, Y. Matsumura, and T. Futamura, “Structure of Austenite of Carbon Steels in High Speed Hot Working Processes”, Tetsu-to-Hagane, 70, pp.2112–2119. (1984)
[32] C.M. Sellars, W.J.M. Tegart, “On the Mechanism of Hot Deformation”, Acta Metall., vol. 14, no. 9, pp. 1136–1138. (1966)
[33] 孫朝陽, 栾京東, 劉賡, 李瑞, 張清東, “AZ31鎂合金熱變形流動應力預測模型”, 金屬學報第48卷, 第7期, 第853-860頁(2012)
[34] C.M. Zener, J.H.Hollomon, Jr,” Effect of Strain Rate Upon Plastic Flow of Steel”., J. Appl. Phys., 15, 22 (1944)
[35] Y.C. Lin, M.S. Chen, “Numerical Simulation and Experimental Verification of Microstructure Evolution in a Three Dimensional Hot Upsetting Process”, J. Mater. Process Technol., 209(9): 4578−4583. (2009)
[36] 鑓田 征雄, 秋山 研人, “AZ31 マグネシウム合金板の多パス温間圧延挙動と 圧延条件が機械的性質および成形性に及ぼす影響”, Journal of the JSTP, Vol.50, No.585. (2009)
[37] Alvi, M. Haroon, “Recrystallization Kinetics and Microstructural Evolution in Hot Rolled Aluminum Alloys”, Carnegie Mellon University, PhD thesis (2005)
[38] M.E. Wahabi, J.M. Cabrera, J.M. Prado, “Hot Working of Two AISI 304 steels: A AoMParative study”, Materials Science and Engineering A,343: pp.116-125 (2003)
[39] W. Zhang, H.B. Dong, X. Yang, “Dynamic Recrystallization Behavior of Q550D Ultra-low Carbon Bainitic Steel”, Transactions of Materials and Heat Treatment, 33(12):pp.158-162 (2012)
[40] B. Wang, “Brief Introduction of Tension Test Specimen of Metallic Materials of ASTM”, PTCA, Part A: Physical Testing, Vol. 40, No.9, (2004)