由于金屬玻璃絲的幾乎無塑性,其通常會發(fā)生災(zāi)難性的斷裂。金屬玻璃絲的斷裂機(jī)制主要受剪切帶的萌生和蔓延控制。高脆性金屬玻璃絲的災(zāi)難性斷裂是沒有任何預(yù)兆的,從而表明金屬玻璃絲的使用性能較差。因此,了解金屬玻璃絲的變形與剪切帶之間的關(guān)系對工程應(yīng)用至關(guān)重要。本文研究了室溫條件下Cu₅₀Zr₅₀,Ni₅₆Nb₄₄和Pd₄₀Cu₃₀Ni₁₀P₂₀金屬玻璃絲表面電沉積Cu,Ni和Cu/Ni雙層金屬玻璃絲的拉伸變形行為,強(qiáng)度可靠性和增強(qiáng)塑性。通過X射線衍射儀（XRD）和差示掃描量熱儀（DSC）測試金屬玻璃絲的無定形結(jié)構(gòu)。通過SEM測定斷裂表面形形貌。在金屬玻璃絲的斷裂表面上可以觀察到典型的脈狀圖案和圓形芯。本研究采用的第二種方法是擠出工藝,也稱為冷拔,以均化鑄態(tài)金屬玻璃絲的表面質(zhì)量。第三種方法是將軟韌性金屬（Cu）和硬金屬（Ni）電沉積到金屬玻璃絲的表面以增強(qiáng)其可塑性。通過電化學(xué)沉積技術(shù)將Cu層電沉積在Pd₄₀

【文章頁數(shù)】：152 頁

【學(xué)位級別】：博士

【文章目錄】：
Dedication
Acknowledgements
Abstract
摘要
Chapter 1 Introduction
    1.1 Metallic glasses
        1.1.1 History and development of metallic glasses
        1.1.2 Mechanical and Microstructure aspect of MG wires
        1.1.3 Application potential of MGs and metallic glass wires
    1.2 Literature Review
        1.2.1 Flow and plastic deformation behavior of metallic glasses
        1.2.2 Yielding criterion for metallic glasses
    1.3 Motivation and objectives
Chapter 2 Mechanical characterization of MG wires
    2.1 Introduction
    2.2 Experimental procedure
    2.3 Results
        2.3.1 Mechanical characterization of metallic glass wires
        2.3.2 Fractographies of metallic glass wires
    2.4 Discussion
        2.4.1 Relationship between diameter vs normal stress of MG wires
        2.4.2 Cohesion strength as a function of the diameter of wires
    2.5 Conclusions
    2.5 結(jié)論
Chapter 3 Tensile strength variations and weibull statistics
    3.1 Introduction
        3.1.1 Applications and key issues of CuZr and NiNb wires
        3.1.2 The Weibull modulus and reliability analysis of wires
        3.1.3 Flaw sensitivity or brittleness in metallic glasses
    3.2 Experimental procedure
    3.3 Results
        3.3.1 Mechanical characterization of metallic glass wires
        3.3.2 Statistical analysis of metallic glass wires
    3.4 Conclusions
    3.4 結(jié)論
Chapter 4 Electrochemical deposition and plasticity of metallic glass wires
    4.1 Introduction
        4.1.1 Electrochemical deposition and redox reactions
        4.1.2 Metals (Cu & Ni) electrochemical deposition
        4.1.3 Technique used to improve plasticity of metallic glasses
    4.2 Experimental procedure
    4.3 Results
        4.3.1 Mechanical characterization of Cu-coated metallic glass wires
        4.3.2 Fractographies of Cu-coated metallic glass wires
    4.4 Discussion
        4.4.1 Deformation behavior of Cu-coated metallic glass wires
    4.5 Conclusions
    4.5 結(jié)論
Chapter 5 Cu/Ni bilayer electrochemical deposition
    5.1 Introduction
        5.1.1 Electrodeposition of Cu/Ni onto the metallic glasses
        5.1.2 Cu/Ni bilayer coating onto Ni56Nb44 MG wires
    5.2 Experimental procedure
    5.3 Results
        5.3.1 Mechanical characterization of Cu/Ni coated metallic glass wires
        5.3.2 Tensile stress-strain curves of coated NiNb MG wires
    5.4 Discussion
        5.4.1 Fractographies of bilayered Cu/Ni-coated MG wires
    5.5 Conclusions
    5.5 結(jié)論
Chapter 6 Overall conclusions and expectations
    6.1 Overall conclusions
    6.1 總體結(jié)論
    6.2 Expectations
    6.2 期望
    6.3 Concluding Remarks
    6.3 結(jié)束語
References
Curriculum Vitae
Publications
Conference Contributions



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