臺灣博碩士論文加值系統

中文摘要
本文所探討之主題為非可銲性鋁鈧合金受動態剪切荷載下之塑性變形行為，利用霍普金森扭轉試驗機所產生之一維彈性扭轉波傳效應來達到所需之動態剪切行為。其實驗所設定之條件為-150℃、25℃、300℃之環境溫度下，應變速率800 、1500 、2200 、2800 等四種不同的扭轉荷載速率。由最後所得之巨觀機械性質與破壞特性，來探討溫度與應變速率兩者於動態剪切荷載下對材料塑變行為之影響與關係，並引入一構成方程式用以描述鋁鈧合金於高速動態剪切荷載下之塑變過程，以利於工程設計與模擬分析之用。
於巨觀分析中，依實驗所得之結果可知，非可銲性鋁鈧合金受剪應變速率與環境溫度影響相當顯著。其影響直接顯示在剪應力-剪應變曲線上，而由此所衍生與代表的物理性質變化，如：加工硬化率、降伏剪強度、應變速率敏感係數、溫度敏感係數與活化能等。同時揭示應變速率強化效應與溫度熱軟化效應對材料機械性質之影響。
於破壞特性分析中，對經過不同實驗條件後之試片進行SEM與OM之拍攝，並進行微硬度之測試。藉由拍攝局部破斷面圖相、韌窩形貌、析出物形貌與剪切帶及塑變流線形貌，來驗證實驗準確性。同時，從破壞分析與巨觀機械性質間之關係來探討鋁鈧合金於高速剪切荷載下塑變行為之特性與成因。最後，引入Kobayashi＆Dodd模式之構成方程式來嘗試描述非可銲性鋁鈧合金於不同溫度下之高速剪切塑變行為，並從中得到與實驗值相當一致的高精確性。

This study uses the torsional split-Hopkinson bar to investigate the shear response and fracture characteristics of unweldable Al-Sc alloy during mechanical testing at shear strain rates of 800 s-1, 1500 s-1, 2200 s-1 and 2800 s-1 and temperatures of -150 , 25 and 300 . The experimental results show that both the shear strain rate and the temperature have a significant effect on the shear properties of the Al-Sc alloy. At a constant temperature, the shear stress, fracture shear strain, work hardening rate, yielding shear strength, work hardening coefficient, strain rate sensitivity and temperature sensitivity all increase with increasing strain rate. However, the inverse tendency is observed with increasing temperature at a constant strain rate. It is found that the Kobayashi and Dodd constitutive equation provides accurate predictions of the high strain rate shear plastic behaviour of unweldable Al-Sc alloy. SEM fractographic observations reveal that the fracture surfaces are characterized by a dimple-like structure. The density of the dimples increase with increasing strain rate at a constant temperature, or with an increasing temperature at a constant strain rate. The presence of precipitates in the fracture surface indicates that the fracture initiates at the interface of the matrix and the precipitates. Finally, twisted shear bands are observed on the equatorial plane of the gauge length section of the deformed specimens. The microhardness of these shear bands increases with the strain rate, but decreases with the temperature as a result of different work hardening effects.

總目錄
ABSTRACT I
中文摘要 II
誌 謝 III
總目錄 IV
表目錄 VII
圖目錄 IX
符號說明 XIV
第一章 前言 1
第二章 理論與文獻回顧 5
2-1 鋁合金之介紹 5
2-1-1 鋁合金之處理 5
2-1-2 合金成份對鋁合金之影響[32] 6
2-1-3 鋁合金之析出硬化[33,34] 7
2-2 鋁鈧合金之介紹[35] 8
2-3 塑性變形之機械測試類別 10
2-4 一維扭轉波傳理論 12
2-5 霍普金森扭轉試驗機原理 14
2-6 材料塑性變形行為之特性 17
2-7 材料變形構成方程式 20
第三章 實驗方法與步驟 34
3-1試件製作 34
3-2 實驗儀器設備 35
3-2-1 霍普金森扭轉試驗機 35
3-2-3 掃描式電子顯微鏡 (SEM) 36
3-2-4 光學顯微鏡 (OM) 37
3-2-5 微小硬度試驗機 (Micro-Hardness Tester) 37
3-3 實驗方法與步驟 37
3-3-1 動態扭轉試驗 37
3-3-2 破斷面之觀察 (SEM) 39
3-3-3 試件金相之觀察 (OM) 39
3-3-4 試件之微硬度分析 39
第四章 實驗結果與討論 44
4-1 剪應力-剪應變曲線之討論 44
4-2 加工硬化率之探討 45
4-3 應變速率效應 48
4-4 溫度效應 49
4-5 活化能 50
4-6 理論溫升量 53
4-7 材料變形構成方程式 54
4-8 微觀分析 55
4-8-1 破壞形貌觀察 (SEM) 55
4-8-1-1 試件破斷面形貌之觀察 55
4-8-1-2 試件破壞形貌之觀察 56
4-8-1-3 析出物之觀察 57
4-8-2 金相組織觀察 (OM) 58
第五章 結論 104
參考文獻 106

參考文獻
1.Y. Bai and B. Dodd, Adiabatic Shear Localization, Pergamon Press, pp. 80-91, 1992.
2.Gabriel M. Novotny, Alan J. Ardell, “Precipitation of in binary Al-Sc alloys.” Materials Science and Engineering A, Vol. 318, pp. 144-154, 2001.
3.E. A. Marquis, D. N. Seidman, “Nanoscale Structural Evolution of Precipitates in Al(Sc) Alloys,” Acta Materialia, Vol. 49, pp. 1909-1919, 2001.
4.S. Lathabai and P. G. Lloyd, “The Effect of Scandium on the Microstructure, Mechanical Properties and Weldability of a Cast Al-Mg Alloy,” Acta Materialia, Vol. 50, pp. 4275-4292, 2002.
5.Yu. A. Filatov, V. I. Yelagin and V. V. Zakharov, “New Al-Mg-Sc Alloys,” Materials Science and Engineering A, Vol. 280, pp. 97-101, 2000.
6.D. N. Seidman, E. A. Marquis and D. C. Dunand, “Precipitation Strengthening at Ambient and Elevated Temperatures of Heat-Treatable Al(Sc) Alloys,” Acta Materialia, Vol. 50, pp. 4021-4035, 2002.
7.K. Venkateswarlu, L. C. Pathak, A. K. Ray, Goutam Das, P. K. Verma, M. Kumar and R. N. Ghosh, “Microstructure, Tensile Strength and Wear Behaviour of Al-Sc Alloy,” Materials Science and Engineering A, Vol. 383, pp. 374-380, 2004.
8.Kun Yu, Wenxian Li, Songrui Li, Jun Zhao, “Mechanical properties and microstructure of aluminum,” Materials Science and Engineering A, Vol. 368, pp. 88-93, 2004.
9.E. A. Marquis, D. N. Seidman and D. C. Dunand, “Effect of Mg Addition on the Creep and Yield Behavior of an Al-Sc Alloy,” Acta Materialia, Vol. 51, pp. 4751-4760, 2003.
10.Yu. V. Milman, D. V. Lotsko and O. I. Sirko, “’Sc Effect’ of Improving Mechanical Properties in Aluminum Alloys,” Materials Science Forum, Vol. 331, pp. 1107-1112, 2000.
11.B. A. Parker, Z. F. Zhou and P. Nolle, “The Effect of Small Additions of Scandium on the Properties of Aluminum Alloys,” Journal of Materials Science, Vol. 30, pp. 452-458, 1995.
12.M. N. Desmukh, R. K. Pandey and A. K. Mukhopadhyay, “Fatigue Behavior of 7010 Aluminum Alloy Containing Scandium,” Scripta Materialia, Vol. 52, pp. 645-650, 2005.
13.C. Watanabe, C. Y. Jin, R. Monzen and K. Kitagawa, “Low-cycle Fatigue Behavior and Dislocation Structure of an Al-Mg-Sc Alloy,” Materials Science and Engineering A, Vol. 387-389, pp. 552-555, 2004.
14.T. Wirtz, G. , A. Gysler, B. Lenczowski and R. Rauh, “Fatigue Properties of the Aluminum Alloys 6013 and Al-Mg-Sc,” Materials Science Forum, Vol. 331, pp. 1489-1494, 2000.
15.O. Roder, T. Wirtz, A. Gysler and G. , “Fatigue Properties of Al-Mg Alloys with and without Scandium,” Materials Science and Engineering A, Vol. 234-236, pp. 181-184, 1997.
16.N. Balasubramanian, Terence G. Langdon, “An analysis of superplastic flow after processing by ECAP,” Materials Science and Engineering A, Vol. 410–411, pp. 476-479, 2005.
17.F. Musin, R. Kaibyshev, Y. Motohashi and G. Itoh, “High Strain Rate Superplasticity in a commercial Al-Mg-Sc Alloy,” Scripta Materialia, Vol. 50, pp. 511-516, 2004.
18.K. T. Park, D. Y. Hwang, Y. K. Lee, Y. K. Kim and D. H. Shin, “High Strain Rate Superplasticity of Submicrometer Grained 5083 Al Alloy Containing Scandium Fabricated by Severe Plastic Deformation,” Materials Science and Engineering A, Vol. 341, pp. 273-281, 2003.
19.D. W. Suh, S. Y. Lee, K. H. Lee, S. K. Lim and K. H. Oh, “Microstructural Evolution of Al-Zn-Mg-Cu-(Sc) Alloy during Hot Extrusion and Heat Treatment,” Journal of Materials Processing Technology, Vol. 155-156, pp. 1330-1336, 2004.
20.S. Celotto and T. J. Bastow, “45Sc Nuclear Magnetic Resonance Analysis of Precipitation in Dilute Al-Sc Alloys,” Philosophical Magazine A, Vol. 80, No. 5, pp. 1111-1125, 2000.
21.T. Torma, E. Kovacs-Csetenyi, T. Turmezey, T. Ungar and I. Kovacs, “Hardening Mechanisms in Al-Sc Alloys,” Journal of Materials Science, Vol. 24, pp. 3924-3927, 1989.
22.L. I. Kaygorodova and V. P. Domashnikov, “Investigation of the Influence of Scandium of the Structure and Properties of an Aluminum-Magnesium Alloy during Natural Ageing,” Physics of Metals and Metallography, Vol. 68, No. 4, pp. 160-166, 1989.
23.N. Blake and M. A. Hopkins, “Constitution and Age Hardening of Al-Sc Alloys,” Journal of Materials Science, Vol. 20, pp. 2861-2867, 1985.
24.M. Ye. Drits, L. B. Ber, YU. G. Bykov, L. S. Toropova and G. K. Anastas’eva, “Ageing of Alloy Al-0.3 at.% Sc,” Physics of Metals and Metallography, Vol. 57, No. 6, pp. 118-126, 1984.
25.M. J. Jones and F. J. Humphreys, “Interaction of Recrystallization and Precipitation: The Effect of Al3Sc on the Recrystallization Behaviour of Deformed Aluminum,” Acta Materialia, Vol. 51, pp. 2149-2159, 2003.
26.Y. W. Riddle and T. H. Sanders, Jr., “Contribution to Al3Sc to Recrystallization Resistance in Wrought Al-Sc Alloys,” Materials Science Forum, Vol. 331, pp. 939-944, 2000.
27.T. D. Rostova, V. G. Davydov, V. I. Yelagin and V. V. Zakharov, “Effect of Scandium on Recrystallization of Aluminum and Its Alloys,” Materials Science Forum, Vol. 331, pp. 793-798, 2000.
28.Y. Miura, T. Shioyama and D. Hara, “Recrystallization of Al-3Mg and Al-3Mg-0.2Sc Alloys,” Materials Science Forum, Vol. 217-222, pp. 505-510, 1996.
29.M. Ferry, N. E. Hamilton and F. J. Humphreys, “Continuous and Discontinuous Grain Coarsening in a Fine-Grained Particle-Containing Al-Sc Alloy,” Acta Materialia, Vol. 53, pp. 1097-1109, 2005.
30.S. Iwamura and Y. Miura, “Loss in Coherency and Coarsening Behavior of Al3Sc Precipitates,” Acta Materialia, Vol. 52, pp. 591-600, 2004.
31.J. R. Davis, Aluminum and Aluminum Alloys, ASM Specialty Handbook, pp. 31, 1994.
32.John E. Hatch, Aluminum Properties and Physical Metallurgy, American Society for Metals, pp. 224-241, 1984.
33.Robert E. Reed-Hill, Reza Abbaschian, Physical Metallurgy Principle 3rd, PWS Publishing Company, pp. 515-537.
34.P. Ratchev, B. Verlinden, P. De Smet, P. Van Houtte, “Precipitation Hardening of an Al±4.2 wt% Mg±0.6 wt% Cu alloy,” Acta Metallurgica, Vol. 46, No. 10, pp. 3523-3533. 1998.
35.J. Røyset, N. Ryum,” Scandium in aluminium alloys”, International Materials Reviews, Vol. 50, No.1, pp. 19-44, 2005.
36.M. A. Meyers and L. E. Murr, Shock Waves and High-Strain-Rate Phenomena in Metals, Plenum Press, pp. 129-167, 1981.
37.ASM Handbook Committee, Metals Handbook, American Society for Metals, pp. 215-230, 1978.
38.U. S. Lindholm and L. W. Yeakly, “High Strain Rate Testing: Tension and Compression,” Experimental Mechanics, Vol. 3, pp. 81-88, 1983.
39.M. A. Meyers, Dynamic Behavior of Materials, A Wiley-Interscience Publication, pp. 23-65, 1994.
40.D. Klahn, A. K. Mukherjee and J. E. Dorn, “Proceedings of the 2nd International Conference on the Strength of Metals and Alloys,” Vol. III, ASM, pp. 951, 1970.
41.J. D. Campbell, “Dynamic Plasticity: Macroscopic and Microscopic Aspects,” Materials Science and Science Engineering, Vol. 12, pp. 3-21, 1973.
42.J. D. Campbell and W. G. Ferguson, “The Temperature and Strain-Rate Dependence of the Shear Strength of Mild Steel,” Philosophical Magazine, Vol. 21, pp. 63-82, 1970.
43.A. M. Eleiche and J. D. Campbell, “Strain-Rate Effects During Reverse Torsional Shear,” Experimental Mechanics, Vol. 16, pp. 281-290, 1976.
44.J. Harding and J. Huddart, “The Use of the Double-Notch Shear Test in Determining the Mechanical Properties of Uranium at Very High Rates of Strain,” Proc. 2nd Conf. Mechanical Properties of Materials at High Rates of Strain, Inst. Physics, pp. 49-61, 1980.
45.A. Seeger, “The Generation of Lattice Defects by Moving Dislocations, and its Application to the Temperature Dependence of the Flow-Stress of FCC Crystals,” The Philosophical Magazine, Vol. 46, pp. 1194-1217, 1955.
46.U. S. Lindholm and L. M. Yeakly, “Dynamic Deformation of Single and Polycrystalline Aluminum,” Journal of Mechanics and Physics of Solids, Vol. 13, pp. 41-49, 1965.
47.H. Conrad, “Thermally Activated Deformation of Metals,” Journal of Metals, pp. 582-588, 1964.
48.W. G. Ferguson, A. Kumar and J. E. Dorn, “Dislocation Damping in Aluminum at High Strain Rates,” Journal of Applied Physics, Vol. 38, pp. 1863-1869, 1967.
49.J. D. Campbell and A. R. Dowling, “The Behaviour of Materials Subjected to Dynamic Incremental Shear Loading,” Journal of Mechanics and Physics of Solids, Vol. 18, pp. 43-63, 1970.
50.J. Harding, “The Effect of High Strain Rate on Material Properties,” Materials at High Strain Rate on Material Properties, pp. 133-186, 1987.
51.Y. Bai and B. Dodd, Adiabatic Shear Localization, Pergamon Press, pp. 104-124, 1992.
52.J. D. Campbell, A. M. Eleiche, and M. C. C. Tsao, Fundamental Aspects of Structural Alloy Design, Plenum Publishing Corp. New York, pp. 545-563, 1977.
53.R. W. Klopp, R. J. Clifton and T. G. Shawki, “Pressure Shear Impact and Dynamic Viscoplastic Response of Metals,” Mechanics of Materials, Vol. 4, pp. 375-385, 1985.
54.F. J. Zerilli and R. W. Armstrong, “Dislocation-Mechanics-Based Constitutive Relations for Material Dynamics Calculations,” Journal of Applied Physics, Vol. 61, pp. 1816-1825, 1987.
55.F. J. Zerilli and R. W. Armstrong, “Constitutive Equation for HCP Metals and High Strength Alloy Steels,” in High Strain Rate Effects on Polymer, Metal and Ceramic Matrix Composites and other Advanced Materials, AD-Vol. 48, pp. 121-126, 1995.
56.H. Kobayashi and B. Dodd, “A Numerical Analysis for the Formation of Adiabatic Shear Bands Including Void Nucleation and Growth,” International Journal of Impact Engineering, Vol. 8, pp. 1-13, 1989.
57.A. S. Khan and H. Zhang, “Mechanically Alloyed Nanocrystalline Iron and Copper Mixture: Behavior and Constitutive Modeling over a Wide Range of Strain Rates,” International Journal of Plasticity, Vol. 16, pp. 1477-1492, 2000.
58.R. Liang and A. S. Khan, “A Critical Review of Experimental Results and Constitutive Models for BCC and FCC Metals over a Wide Range of Strain Rates and Temperatures,” International Journal of Plasticity, Vol. 15, pp. 963-980, 1999.
59.V. V. Zakharov,“Commercial Aluminium Alloys with Scandium additions,” Metal Science and Heat Treatment, Vol. 37, No. 7, pp.21-23, 1995.
60.V. V. Zakharov and T. D. Rostova, “High-Strength Weldable Alloy 1970 Based on The Al-Zn-Mg System,” Metal Science and Heat Treatment, Vol. 47, No. 4, pp.131-138, 2005.
61.G. E. Totten and D. S. MacKenzie, Handbook of Aluminum, Volume 1, Physical Metallurgy and Processes, pp. 881-914,2003.
62.L. Shi and D. O. Northwood, “The Mechanical Behavior of an AISI Type 310 Stainless Steel,” Acta Metallurgica et Materialia, Vol. 43, pp. 453-460, 1995.
63.B. Q. Han, E. J. Lavernia and F. A. Mohamed, “Mechanical Behavior of a Cryomilled Near-Nanostructured Al-Mg-Sc Alloy,” Metallurgical and Materials Transactions A, Vol. 36A, pp. 345-355, 2005.
64.Y. Harada and D. C. Dunand, “Creep Properties of Al3Sc and Al3(Sc, X) Intermetallics,” Acta Materialia, Vol. 48, pp. 3477-3487, 2000.
65.C. Watanabe, T. Kondo and R. Monzen, “Coarsening of Al3Sc Precipitates in an Al-0.28 Wt Pct Sc Alloy,” Metallurgical and Materials Transactions A, Vol. 35A, pp. 3003-3008, 2004.
66.R. Kapoor and S. Nemat-Nasser, “Determination of Temperature Rise during High Strain Rate Deformation,” Mechanics of Materials, Vol. 27, pp. 1-12, 1998.