跳到主要內容

簡易檢索 / 詳目顯示

回結果列表
研究生： 張仲凱
Chung-Kai Chang
論文名稱： 使用繞射技術研究環境溫度效應對碳碳複材的影響
Study of Environmental Thermal Effects on Carbon-carbon Composite by Using X-ray Diffraction
指導教授： 黃爾文
E-Wen Huang
口試委員:
學位類別： 碩士
Master
系所名稱： 工學院 - 化學工程與材料工程學系
Department of Chemical & Materials Engineering
畢業學年度： 100
語文別： 英文
論文頁數： 84
中文關鍵詞： 同步輻射繞射 、分子模擬 、碳碳複材
外文關鍵詞： Carbon-carbon composites materials, Synchrotron X-rya diffraction, Molecular Dynamics simulation
相關次數： 點閱：12  下載：0 
分享至:
查詢本校圖書館目錄 查詢臺灣博碩士論文知識加值系統 勘誤回報

    • 超高溫氣冷式反應器(Very High Temperature Gas Reactor, VHTGR)是目前世界上備受矚目的發展中核子反應爐，由於對材料具有高溫穩定特性、高熱傳導特性、低中子吸收面積的要求，碳碳複合材料成為理想的候選材料之一，碳碳複合材料使用於反應爐中的控制棒及控制棒導管，在將近1000℃的高溫操作環境下，了解碳碳複材的溫度特性是相當重要的議題。
    碳碳複材是由碳纖維(carbon fiber)為骨架，由碳母材(matrix)以氣相或液相方式滲透到碳纖維預成形件(preform)中而形成碳碳複材，因此碳纖維種類、編織方式以及成長基材的方法是影響碳碳複材性質最主要的三個因素。
    本研究探討的主題為溫度效應對碳纖維、基材的影響，研究的方法為使用一般X光繞射(in house X-ray diffraction)及同步輻射繞射(Synchrotron X-ray diffraction)，觀察碳碳複材在不同溫度下微結構的改變。研究的碳碳複材類型是以聚丙烯腈基(Polyacrylonitrile)為碳纖維，三維編織成預成形件，並以瀝青(Pitch-based)為基材。溫度效應的實驗是將樣品置入通空氣的加熱爐中，環境溫度分別是500℃、700℃、900℃，置入時間分別為2分鐘及4分鐘。
    在本研究中，一般X-ray繞射與同步輻射繞射最大的不同，在於訊號的強度以、樣品的取樣區域，而一般X-ray觀察的區域是樣品的整體訊號，而同步輻射則能控制入射光的位置而獲得樣品不同區域訊號，此外同步輻射使用二維偵檢器收集訊號，能藉由二維繞射環上不同方向角來判斷碳碳複材的優選方向，由於碳纖維與基材的修選方向不同，因此能透過上述的訊號特性，分別討論溫度效應對碳纖維與基材的影響。繞射的結果顯示，c軸與a軸的晶格常數在500℃時為收縮，而隨著溫度提高至700℃、900℃，此收縮效應變成膨脹，由分子模擬的結果可以解釋500℃的收縮現象是由於材料中的缺陷及原子受熱後達穩定位置，而溫度大於500℃的膨脹現象是由溫度效應所造成。繞射強度隨繞射環上不同的積分方位角改變，顯示碳碳複材具有高度優選方向特性，從方向角的強度分布發現加熱過程中產生的熱應力造成晶面重組。
    此論文對實驗室的主要貢獻為，建立一套研究方法來分析同步輻射繞射的數據，包括了解繞射實驗時入射光與樣品取樣區的關係(mapping)、批次處理大量繞射數據的方法、使用新的軟體擬合及呈現繞射數據、建立碳碳複合材料的研究背景、發現碳碳複材優選方向特性對微結構的影響。

    Carbon-carbon composites are deemed as candidate materials for application in very high temperature reactors. In a very high temperature reactor, carbon-carbon composite materials would experience severe environmental impacts of high temperatures. As a result, we applied X-ray diffraction to investigate the microstructure change of carbon-carbon composite materials as a function of temperature. In this study, the samples were prepared in the format of a three-dimensional pitch-based carbon-carbon composite. The samples were heated to 500℃, 700℃, 900℃ for 2min and 4min, respectively. In order to understand the temperature effect on carbon-carbon composite, we facilitated the high penetration of the synchrotron X-ray diffraction at National Synchrotron Radiation Research Center to examine the evolution of microstructures subjected to heat treatment. The results show that the lattice parameters of a-axis and c-axis evolve upon heating. The varying slopes of lattice strain versus temperature and reveal the temperature effect. The molecular dynamics simulation results also agree with the temperature effect within 500℃.

    TABLE OF CONTENTS 中文摘要 I ABSTRACT III 誌謝 IV TABLE OF CONTENTS VI LISTS OF FIGURES VIII LISTS OF TABLES X 1 CHAPTER 1: INTRODUCTION 1 1.1 Research Background 1 1.1.1 Generation IV nuclear energy systems 2 1.1.2 Types of reactors 2 1.1.3 Very High Temperature Reactor 3 1.1.4 Carbon-Carbon – Composite Materials 4 1.2 Motivation 6 2 CHAPTER 2: MATERIALS, EXPERIMENTS AND METHODS 12 2.1 Materials: Carbon-Carbon Composites Materials 12 2.2 Principle of X-ray diffraction 12 2.2.1 In-house X-rays: 13 2.2.2 Synchrotron radiation 14 2.2.3 Data interpretation 14 2.3 Research Structure 15 2.4 Experiments 16 2.4.1 Heat Treatment 16 2.4.2 In-house and synchrotron X-ray Diffraction 16 2.5 Data Analysis 17 2.5.1 Diffraction Data Analysis by using fit2D 17 2.5.2 Characterization of Orientation-dependent fiber arrangement 18 2.5.3 Diffraction pattern simulation by using Powder Cell 19 2.6 Molecular Dynamics Simulation 19 3 CHAPTER 3: RESULTS 28 3.1 In-House X-ray Diffraction 28 3.1.1 Degree of graphitization (g) and Crystallite dimension (Lc) analysis 28 3.2 Synchrotron X-ray Diffraction 29 3.3 Molecular Dynamics Simulation 29 4. CHAPTER 4: DISCUSSION 44 CHAPTER 5: SUMMARY 50 LISTS OF REFERENCE 52 APPENDIXS 53 Fit2D 操作 53 ImageJ 操作 59 PowderCell 操作 62 Sigmaplot 操作 65

    1. Virgil''ev, Y.S. and I.P. Kalyagina, Carbon–Carbon Composite Materials. Inorganic Materials, 2004. 1(40): p. 33.
    2. Baccaglini, G., et al., Very High Temperature Reactor: Survey of Materials Research and Development Needs to Support Early Deployment. 2003.
    3. http://www.gen-4.org/Technology/evolution.htm.
    4. http://www.gen-4.org/Technology/systems/vhtr.htm.
    5. Will, G., Powder Diffraction: The Rietveld Method and the Two Stage Method to Determine and Refine Crystal Structures from Powder Diffraction Data. 2010: Springer.
    6. 吳泰伯 and 許樹恩, 材料科學叢書1：X光繞射原理與材料結構分析. 1996: 中國材料科學學會. 127.
    7. 汪建民, 材料科學叢書2：材料分析. 1998: 中國材料科學學會.
    8. Hutchings, M.T., et al., Introduction to the Characterization of Residual stresss by neutron diffraction. 2005: Taylor & Francis Group.
    9. Savage, G., Carbon-Carbon Composites. 1993: Chapman & Hall.
    10. Glatter, O. and O. Kratky, Small-angle X-ray Scattering. 1982: Academic Press.
    11. Kraus, W. and G. Nolze, POWDER CELL - a program for the representation and manipulation of crystal structures and calculation of the resulting X-ray powder patterns. Journal of Applied Crystallography, 1996. 29(3): p. 301-303.
    12. Appleyard, S.P. and B. Rand, The effect of fibre-matrix interactions on structure and propperty changes during the fabrication of unidirectional carbon/carbon composites. Carbon, 2002. 40: p. 817-834.
    13. Kelly, B.T., Physics of graphite. 1981, UK: Applied science publishers.
    14. Yuan, G., et al., Graphite blocks with preferred orientation and high thermal conductivity. Carbon, 2012. 50: p. 175-182.
    15. Chang, C.K., et al., A synchrotron X-ray study on the Wigner Effect of the irradiated nuclear-grade graphite. Procedia Engineering, 2012. 36: p. 7-12.
    16. Luo, X., J.-C. Robin, and S. Yu, Efffect of temperature on graphite oxidation behavior. Nuclear Engineering and Design, 2004. 227: p. 273-280.

    QR CODE
    :::