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博碩士論文 etd-0808115-141756 詳細資訊
Title page for etd-0808115-141756
論文名稱
Title
以分子靜力學模擬預測鎢奈米線之機械性質
Examination on the mechanical properties of tungsten nanowires by molecular statics simulation
系所名稱
Department
畢業學年期
Year, semester
語文別
Language
學位類別
Degree
頁數
Number of pages
85
研究生
Author
指導教授
Advisor
召集委員
Convenor
口試委員
Advisory Committee
口試日期
Date of Exam
2015-07-20
繳交日期
Date of Submission
2015-09-08
關鍵字
Keywords
分子靜力學、鎢、極限強度、圈彎測試法、拉伸測試法
intrinsic strength, loop test, Tungsten, tension test, molecular statics
統計
Statistics
本論文已被瀏覽 5714 次,被下載 834
The thesis/dissertation has been browsed 5714 times, has been downloaded 834 times.
中文摘要
實驗上,圈彎測試法已被用於預測材料之極限強度,而本研究將以分子靜力學模擬圈彎測試法並比較傳統拉伸測試法所得到的機械性質。首先,我們比較Finnis-Sinclair原子鑲嵌法、合金原子鑲嵌法與第二鄰近修正式原子鑲嵌法這三種描述鎢材料的勢能函數,並用此三種不同的勢能函數模擬拉伸測試鎢塊材模型,再分別與實驗值做比較。得到的結果為第二鄰近修正式原子鑲嵌法計算出的機械性質最接近實驗值,因此本研究的模擬採用此勢能函數。而為了避免鎢奈米線的尺寸影響其機械性質,我們分析鎢奈米線的尺寸效應,並選取鎢奈米線最大直徑為12奈米。在該尺寸下之鎢奈米線已排除了明顯的尺寸效應,並且適合用於分子模擬計算。
我們分別模擬以圈彎測試法及傳統拉伸測試法計算出鎢奈米線的極限應變。為了模擬有缺陷的天然結構,我們隨機刪除原子,創造帶有隨機孔隙缺陷的鎢奈米線結構,並比較以傳統拉伸測試法以及圈彎測試法得到的結果。結果顯示隨機孔隙缺陷會強烈影響傳統拉伸測試法的結果,而圈彎測試法的結果受的影響較低。因此,利用圈彎測試法預測帶缺陷結構的極限強度將會更趨近完美結構的極限強度,未來有機會成為預測材料極限強度的新主流。
Abstract
The new improved loop test had been examined to predict the limited strength of nanowires. We employ molecular statics (MS) simulations to obtain the mechanical properties of nanowire based on the improved loop test method, and compared with the traditional tensile test method in this study. First, we compared Finnis-Sinclair EAM potential, alloy EAM potential and 2nn-MEAM potential for simulating tension tests of bulk tungsten (W) and compared with experimental data. The simulation results indicated the 2nn-MEAM potential is the best force field for describing the mechanical behavior of bulk tungsten. Furthermore, the size-effects of W nanowires were investigated in order to avoid the influences of model dimension. The tungsten nanowire with diameter of 12 nm was chosen because it avoided the obvious size-effect and the model was suitable to simulate by using MS.
The loop test and the traditional tensile test are simulated to obtain the maximum strain of W nanowires. In order to construct the nature structure with defects, we create random vacancies in the tungsten nanowires by deleting random atoms. Moreover, we compared the results from perfect and defective structures with the two methods by tension and bending simulations. The results present the random vacancies cannot influence the new loop test significantly, instead of traditional tensile test. Therefore, the new loop test becomes the mainstreaming means for predicting the limited strengths of defective and perfect structures in the nanoscale mechanical analyses.
目次 Table of Contents
論文審定書 i
致謝 ii
中文摘要 iii
英文摘要 iv
目錄 v
圖次 vii
表次 x
第一章 緒論 1
1.1研究目的與動機 1
1.2鎢材料的相關研究與實驗合成鎢奈米線結構文獻回顧 2
1.3奈米效應與尺寸效應文獻回顧 4
1.4傳統拉伸試驗法文獻回顧 7
1.5圈彎測試法文獻回顧 12
1.6論文架構 15
第二章 模擬方法與理論介紹 16
2.1 分子靜力學理論 (共軛梯度法) 17
2.2勢能函數 19
2.2.1 EAM勢能 19
2.2.2 MEAM勢能 20
2.3原子級應力分析 22
2.4週期邊界 24
2.5鄰近原子表列數值方法 25
2.5.1截斷半徑法 25
2.5.2維理表列法 26
2.5.3巢室表列法 27
2.5.4維理結合巢室表列法 28
2.6模擬步驟 29
第三章 結果與討論 32
3.1分子靜力學模型介紹 32
3.1.1 模擬單晶鎢塊材物理模型 32
3.1.2 模擬六角單晶鎢奈米線物理模型 33
3.1.3 拉伸測試模型介紹 34
3.1.4 圈彎測試模型介紹 35
3.2勢能函數之選擇 36
3.3分析尺寸效應 39
3.4模擬拉伸測試法預測大尺寸鎢奈米線的機械性質 41
3.5模擬圈彎測試法預測大尺寸鎢奈米線的機械性質 55
3.6模擬拉伸與圈彎測試法比較 65
第四章 結論與未來展望 66
4.1 結論 66
4.2 未來展望 67
參考文獻 68
參考文獻 References
[1] S. Wang, Y. He, H. Huang, J. Zou, G. J. Auchterlonie, L. Hou, et al., "An improved loop test for experimentally approaching the intrinsic strength of alumina nanoscale whiskers," Nanotechnology, vol. 24, p. 285703, Jul 19 2013.
[2] H. Huang, Y. Q. Wu, S. L. Wang, Y. H. He, J. Zou, B. Y. Huang, et al., "Mechanical properties of single crystal tungsten microwhiskers characterized by nanoindentation," Materials Science and Engineering a-Structural Materials Properties Microstructure and Processing, vol. 523, pp. 193-198, Oct 2009.
[3] V. Cimalla, C. C. Rohlig, J. Pezoldt, M. Niebelschutz, O. Ambacher, K. Bruckner, et al., "Nanomechanics of single crystalline tungsten nanowires," Journal of Nanomaterials, 2008.
[4] S. Z. Li, X. D. Ding, J. Li, X. B. Ren, J. Sun, and E. Ma, "High-Efficiency Mechanical Energy Storage and Retrieval Using Interfaces in Nanowires," Nano Letters, vol. 10, pp. 1774-1779, May 2010.
[5] S. Wang, Y. He, X. Fang, J. Zou, Y. Wang, H. Huang, et al., "Structure and Field-Emission Properties of Sub-Micrometer-Sized Tungsten-Whisker Arrays Fabricated by Vapor Deposition," Advanced Materials, vol. 21, pp. 2387-2392, 2009.
[6] S. Wang, G. Chen, H. Huang, S. Ma, H. Xu, Y. He, et al., "Vapor-phase synthesis, growth mechanism and thickness-independent elastic modulus of single-crystal tungsten nanobelts," Nanotechnology, vol. 24, p. 505705, Dec 20 2013.
[7] Q.-X. Pei, Z.-D. Sha, Y.-Y. Zhang, and Y.-W. Zhang, "Effects of temperature and strain rate on the mechanical properties of silicene," Journal of Applied Physics, vol. 115, p. 023519, 2014.
[8] Z. L. Wang and J. Song, "Piezoelectric Nanogenerators Based on Zinc Oxide Nanowire Arrays," Science, vol. 312, pp. 242-246, April 14, 2006 2006.
[9] F. Yuan and L. Huang, "Molecular dynamics simulation of amorphous silica under uniaxial tension: From bulk to nanowire," Journal of Non-Crystalline Solids, vol. 358, pp. 3481-3487, 2012.
[10] B. Fu, N. Chen, Y. Xie, X. Ye, and X. Gu, "Size and temperature dependence of the tensile mechanical properties of zinc blende CdSe nanowires," Physics Letters A, vol. 377, pp. 2681-2686, 2013.
[11] B. Wei, K. Zheng, Y. Ji, Y. Zhang, Z. Zhang, and X. Han, "Size-dependent bandgap modulation of ZnO nanowires by tensile strain," Nano Lett, vol. 12, pp. 4595-9, Sep 12 2012.
[12] Y. Zhu, Q. Qin, F. Xu, F. Fan, Y. Ding, T. Zhang, et al., "Size effects on elasticity, yielding, and fracture of silver nanowires:In situexperiments," Physical Review B, vol. 85, 2012.
[13] G. Cheng, T. H. Chang, Q. Qin, H. Huang, and Y. Zhu, "Mechanical properties of silicon carbide nanowires: effect of size-dependent defect density," Nano Lett, vol. 14, pp. 754-8, Feb 12 2014.
[14] P. Villain, P. Beauchamp, K. F. Badawi, P. Goudeau, and P. O. Renault, "Atomistic calculation of size effects on elastic coefficients in nanometre-sized tungsten layers and wires," Scripta Materialia, vol. 50, pp. 1247-1251, 2004.
[15] D. Zhang, J. M. Breguet, R. Clavel, L. Phillippe, I. Utke, and J. Michler, "In situ tensile testing of individual Co nanowires inside a scanning electron microscope," Nanotechnology, vol. 20, p. 365706, Sep 9 2009.
[16] W.-H. Chen, H.-C. Cheng, Y.-C. Hsu, R.-H. Uang, and J.-S. Hsu, "Mechanical material characterization of Co nanowires and their nanocomposite," Composites Science and Technology, vol. 68, pp. 3388-3395, 2008.
[17] R. Agrawal, B. Peng, E. E. Gdoutos, and H. D. Espinosa, "Elasticity Size Effects in ZnO Nanowires−A Combined Experimental-Computational Approach," Nano Letters, vol. 8, pp. 3668-3674, 2008/11/12 2008.
[18] Y. Lu, C. Peng, Y. Ganesan, J. Y. Huang, and J. Lou, "Quantitative in situ TEM tensile testing of an individual nickel nanowire," Nanotechnology, vol. 22, p. 355702, Sep 2 2011.
[19] J. H. Irving and J. G. Kirkwood, "The Statistical Mechanical Theory of Transport Processes. IV. The Equations of Hydrodynamics," The Journal of Chemical Physics, vol. 18, pp. 817-829, 1950.
[20] W. W. Wood and F. R. Parker, "Monte Carlo Equation of State of Molecules Interacting with the Lennard‐Jones Potential. I. A Supercritical Isotherm at about Twice the Critical Temperature," The Journal of Chemical Physics, vol. 27, pp. 720-733, 1957.
[21] G. V. Lewis and C. R. A. Catlow, "Potential models for ionic oxides," Journal of Physics C: Solid State Physics, vol. 18, p. 1149, 1985.
[22] V. N. Koparde and P. T. Cummings, "Molecular Dynamics Simulation of Titanium Dioxide Nanoparticle Sintering," The Journal of Physical Chemistry B, vol. 109, pp. 24280-24287, 2005/12/01 2005.
[23] N. Chandra, S. Namilae, and C. Shet, "Local elastic properties of carbon nanotubes in the presence of Stone-Wales defects," Physical Review B, vol. 69, Mar 2004.
[24] N. Tokita, M. Hirabayashi, C. Azuma, and T. Dotera, "Voronoi space division of a polymer: Topological effects, free volume, and surface end segregation," Journal of Chemical Physics, vol. 120, pp. 496-505, Jan 1 2004.
[25] D. Srolovitz, K. Maeda, V. Vitek, and T. Egami, "Structural Defects in Amorphous Solids Statistical-Analysis of a Computer-Model," Philosophical Magazine a-Physics of Condensed Matter Structure Defects and Mechanical Properties, vol. 44, pp. 847-866, 1981.
[26] N. Miyazaki and Y. Shiozaki, "Calculation of mechanical properties of solids using molecular dynamics method," Jsme International Journal Series a-Mechanics and Material Engineering, vol. 39, pp. 606-612, Oct 1996.
[27] M. I. Baskes, "Application of the Embedded-Atom Method to Covalent Materials: A Semiempirical Potential for Silicon," Physical Review Letters, vol. 59, pp. 2666-2669, 12/07/ 1987.
[28] D. C. Rapaport, The art of molecular dynamics simulation, 2nd ed. Cambridge, UK ; New York, NY: Cambridge University Press, 2004.
[29] J. M. Haile, Molecular dynamics simulation : elementary methods. New York: Wiley, 1992.
[30] D. Frenkel and J. P. Hansen, "Understanding liquids: A computer game?," Physics World, vol. 9, pp. 35-40, Apr 1996.
[31] M. P. Allen and D. J. Tildesley, Computer simulation of liquids: Oxford university press, 1989.
[32] D. C. Rapaport, The art of molecular dynamics simulation: Cambridge university press, 2004.
[33] Q. Qin, S. Yin, G. Cheng, X. Li, T.-H. Chang, G. Richter, et al., "Recoverable plasticity in penta-twinned metallic nanowires governed by dislocation nucleation and retraction," Nat Commun, vol. 6, 01/13/online 2015.
[34] M. W. Finnis and J. E. Sinclair, "A simple empirical N-body potential for transition metals," Philosophical Magazine A, vol. 50, pp. 45-55, 1984/07/01 1984.
[35] X. W. Zhou, H. N. G. Wadley, R. A. Johnson, D. J. Larson, N. Tabat, A. Cerezo, et al., "Atomic scale structure of sputtered metal multilayers," Acta Materialia, vol. 49, pp. 4005-4015, 11/14/ 2001.
[36] B.-J. Lee, M. I. Baskes, H. Kim, and Y. Koo Cho, "Second nearest-neighbor modified embedded atom method potentials for bcc transition metals," Physical Review B, vol. 64, 2001.
[37] F. H. Featherston and J. R. Neighbours, "Elastic Constants of Tantalum, Tungsten, and Molybdenum," Physical Review, vol. 130, pp. 1324-1333, 1963.
[38] D. A. Smith and K. M. Bowkett, "The analysis of field-ion micrographs: Stacking faults in tungsten," Philosophical Magazine, vol. 18, pp. 1219-1233, 1968/12/01 1968.
[39] "High Voltage Electron Microscopy. Ed. by P. R. Swann, C. J. Humphreys and M. J. Goringe," Journal of Microscopy, vol. 102, pp. 229-229, 1974.
[40] M. L. Falk and J. S. Langer, "Dynamics of viscoplastic deformation in amorphous solids," Physical Review E, vol. 57, pp. 7192-7205, 06/01/ 1998.
[41] F. Shimizu, S. Ogata, and J. Li, "Theory of Shear Banding in Metallic Glasses and Molecular Dynamics Calculations," MATERIALS TRANSACTIONS, vol. 48, pp. 2923-2927, 2007.
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