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Chan Chun Wai = 納米鈀硅合金的熱性質 / 陳進偉. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2000. / Includes bibliographical references (leaves 18-20). / Text in English; abstracts in English and Chinese. / Chan Chun Wai = Na mi ba gui he jin de re xing zhi / Chen Jinwei. / Acknowledgements --- p.III / Abstract --- p.IV / 摘要 --- p.V / Chapter Chapter One ´ؤ --- Introduction / Chapter 1.1 --- Novel materials in the 21st century --- p.1 / Chapter 1.2 --- What are Nanocrystalline Materials? --- p.1 / Chapter 1.3 --- The superior properties of Nanocrystalline Materials --- p.2 / Chapter 1.4 --- Fabrication of Nanocrystalline Materials --- p.3 / Chapter 1.5 --- Flaws of the as-produced Nanophase Materials --- p.4 / Chapter 1.6 --- Theory of Phase Separation --- p.4 / Chapter 1.7 --- Nucleation and Growth --- p.6 / Chapter 1.7.1 --- Homogeneous nucleation / Chapter 1.7.2 --- Heterogeneous nucleation / Chapter 1.8 --- Spinodal Decomposition / Chapter 1.8.1 --- How SD differs from the classical diffusion process? / Chapter 1.8.2 --- Dynamics of SD / Chapter 1.8.3 --- How can we distinguish SD from Nucleation and Growth? / Chapter 1.8.4 --- Pore-free nanophase materials produced by Liquid Phase SD / Chapter 1.9 --- Thermal properties of the pore-free nanostructured Pd82Si18 Alloy --- p.12 / Chapter 1.9.1 --- A review of grain growth in nanophase materials / Chapter 1.9.2 --- Grain growth study on LSD Pd82Si18 alloy 一 aim and prospect / References --- p.18 / Figures --- p.21 / Chapter Chapter Two 一 --- Experimental / Chapter 2.1 --- Introduction --- p.28 / Chapter 2.2 --- From preparation of samples to microstructure analysis --- p.28 / Chapter 2.2.1 --- Alloying / Chapter 2.2.2 --- Fluxing / Chapter 2.2.3 --- Rapid Solification / Chapter 2.2.4 --- Annealing / Chapter 2.2.5 --- Microstructure analysis / Figures --- p.31 / Chapter Chapter Three ´ؤ --- Results and discussions / Thermal stability of bulk nanostructured alloys prepared by liquid phase spinodal decomposition --- p.34 / References --- p.40 / Table --- p.43 / Figures --- p.44 / Chapter Chapter Four ´ؤ --- Conclusions --- p.61

by Chua Lai Fei Joseph. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1996. / Includes bibliographical references. / by Chua Lai Fei Joseph. / ACKNOWLEDGMENTS --- p.2 / ABSTRACT --- p.3 / Chapter CHAPTER 1: --- INTRODUCTION --- p.5 / Chapter 1.1 --- METALLIC GLASS --- p.5 / Chapter 1.2 --- SOLIDIFICATION PROCESS OF AN ALLOY --- p.7 / Chapter 1.2.1 --- COOLING PATH --- p.7 / Chapter 1.2.2 --- FREE VOLUME MODEL --- p.8 / Chapter 1.2.3 --- NUCLEATION --- p.9 / Chapter 1.2.4 --- LIQUID PHASE SEPARATION --- p.10 / Chapter 1.3 --- IDEAS ON SOME CHARACTERISTIC PARAMETER OF GLASS AND GLASS FORMING ABILITY OF AN METALLIC ALLOY --- p.11 / Chapter 1.3.1 --- CORRELATION FOR THE EXPANSION COEFFICIENT AND THE GLASS TRANSITION TEMPERATURE --- p.11 / Chapter 1.3.2 --- CORRELATION FOR THE GLASS FORMING ABILITY WITH CRYSTALLINE COMPOUNDS/SOLID-SOLUTIONS --- p.12 / REFERENCES --- p.13 / Chapter CHAPTER 2: --- EXPERIMENTAL --- p.17 / Chapter 2.1 --- SAMPLE PREPARATION --- p.17 / Chapter 2.2 --- EXPERIMENTAL DETAILS FOR ALPHA MEASUREMENT --- p.17 / Chapter 2.3 --- EXPERIMENTAL DETAILS FOR FINDING EQUILIBRIUM PHASES AND GLASS FORMING ABILITY OF AN ALLOY --- p.20 / Chapter 2.3.1 --- FINDING EQUILIBRIUM PHASES --- p.20 / Chapter 2.3.2 --- FINDING GLASS FORMING ABILITY --- p.21 / Chapter CHAPTER 3: --- CORRELATION FOR THERMAL EXPANSION COEFFICIENTS OF MOLTEN GLASS FORMING SYSTEMS --- p.28 / REFERENCES --- p.37 / Chapter CHAPTER 4: --- CORRELATION FOR THE GLASS FORMING ABILITY OF PD83.5-XCUXSI16.5 WITH CRYSTALLINE COMPOUNDS/SOLID- SOLUTIONS --- p.38 / Chapter 4.1 --- INTRODUCTION --- p.39 / Chapter 4.2 --- EXPERIMENTAL --- p.39 / Chapter 4.3 --- RESULTS --- p.41 / Chapter 4.4 --- DISCUSSION --- p.43 / REFERENCES --- p.54 / Chapter CHAPTER 5: --- CONCLUSION --- p.55

Graduation date: 2004

Graduation date: 2004

By the investigation of the bulk metallic glass-forming liquids that have very low critical cooling rates, the thermodynamics of metallic glasses can be clarified. For studying thermodynamic properties, such as the specific heat capacity, calorimetry (DSC) is utilized and one of the most used instruments is the differential scanning calorimeter. In this study calorimetry was used to investigate the thermodynamics of the Pd������Ni������Cu������P������ alloy. The specific heat capacity of the liquid and crystalline state, enthalpy, entropy, as well as Gibbs free energy difference between the liquid and crystalline state were measured and evaluated in comparison with previous studies of the alloy. The Pd������Ni������Cu������P������ alloy is known as a metallic glass-forming alloy that has high ability for vitrification without crystallization. By observing the onset of heat flux of the exothermic reactions in the DSC, the time-temperature-transformation diagram can be constructed, and the diagram confirms the high ability for the vitrification for the sample. In addition, the effect of fluxing by B���O��� to reduce heterogeneous nucleation is determined by the TTT-diagram. The enthalpy change during the crystallization was directly measured in experiments in which the sample was held isothermally in the DSC. Both enthalpies, calculated from the specific heat capacity measurements and direct measured enthalpy exactly match each other. The very interesting effect in these experiments is an effect of heat treatment in the samples. Two glass transition temperatures can be noticeably recognized by scanning the exothermic event of the sample with the DSC. The material separates into two undercooled liquids. The two phases that are separated during heat treatment can be described by two different fragility parameters. / Graduation date: 2001

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