中温SPS法制备致密化Si 3 N 4 /LiAlSiO 4 复合材料

发布时间：2021-01-08 04:54

　　本文对用SPS法通过熔融LiAlSiO4制备a-Si3N4和用简单的溶胶凝胶法制备LiYO2进行了研究。尽管具有高强度、低膨胀系数、耐高温冲击和耐化学腐蚀等优良的热力学性能,但是由于Si-N之间具有强的共价键从而导致低的扩散系数,致密化氮化硅的制备依然是一个不小的挑战。近来人们通过液相烧结增加物质的传输性制备了接近于理论密度的氮化硅陶瓷。然而,高成本的添加剂和高的烧结温度限制了氮化硅基陶瓷的应用。因此,高效低成本地制备烧结助剂和最终产物的后续研究成为了我们的主要课题。本论文中,我们用溶胶凝胶法制备了钇氧化锂（LiYO2）,用固相法制备了硅酸锂铝（LiAlSiO4）,这两种材料是中温陶瓷烧结重要的添加剂材料。事实上LiYO2是一种具有碳吸附能力和防暴晒涂层应用的环境友好型材料。它是用锂含量高的前躯体制备的,相比于固相合成反应,这种前躯体可以在更加低的温度下燃烧溶胶凝胶法制备的无定形粉末从而得到高纯的LiYO2粉末。950℃保温6小时,Li（CH3COO）·2H2O和Y（NO3）3·6H2O的摩尔比为2以及1000℃保温6小时,Li（CH3COO）·2H2O和Y（NO3）3·6H2O的摩尔... 

【文章来源】：武汉理工大学湖北省 211工程院校 教育部直属院校

【文章页数】：67 页

【学位级别】：硕士

【文章目录】：
中文摘要
Abstract
Chapter 1:Introduction and Literature Review
    1.1 Introduction
    1.2 Literature review
3N₄">        1.2.1 Crystal structure of Si₃N4

        1.2.2 Sintering and mechanical performance
            1.2.2.1 Particle rearrangement
            1.2.2.2 Solution-reprecipitation
            1.2.2.3 Final densification or solid-state sintering
    1.3 Objective of this study
    1.4 Contents of this study
Chapter 2:Experimental Techniques and Methods applied
    2.1 Raw and starting precursors materials
    2.2 Experimental methods
        2.2.1 Samples preparation
2">            2.2.1.1 Sol-gel preparation of LiYO₂

            2.2.1.2 Solid-state preparation of LiAlSiO₄ glass powder
4 glass">            2.2.1.3 Preparation of nano-powder of LiAlSiO₄ glass
3N₄/LiAlSiO₄ composite material">            2.2.1.4 SPS preparation of Si₃N₄/LiAlSiO₄ composite material
        2.2.2 Performance and structural characterization techniques
            2.2.2.1 X-ray diffraction
            2.2.2.2 Morphology and microstructure analysis
            2.2.2.3 Particle size distribution
            2.2.2.4 Thermal analysis
            2.2.2.5 Infrared spectroscopy
            2.2.2.6 Density
            2.2.2.7 Hardness and fracture toughness
4 and LiYO₂">Chapter 3:Preparation of Additives:LiAlSiO₄ and LiYO₂

    3.1 Sol-gel synthesis and characte rization of LiYO₂

        3.1.1 Experimental procedure
        3.1.2 Results and discussion
            3.1.2.1 Thermal characterization
2">            3.1.2.2 FT-IR characterization of LiYO₂

            3.1.2.3 XRD characterization
            3.1.2.4 SEM characterization
        3.1.3 Conclusion
4">    3.2 Solid-state preparation of LiAlSiO₄

        3.2.1 Experimental procedure
        3.2.2 Results and discussion
            3.2.2.1 Phase characterization
            3.2.2.2 Morphology and particle size distribution
        3.2.3 Conclusion
3N₄/LiAlSiO₄ Composite material">Chapter 4:SPS Sintering of Si₃N₄/LiAlSiO₄ Composite material
    4.1 Densification and mechanism
        4.1.1 Effect of temperature
        4.1.2 Effect of pressure
        4.1.3 Fracture surface
    4.2 Performance of sintered samples
3N₄">    4.3 Extent densification and the α/β transformation in Si₃N₄

    4.4 Influence of holding time
    4.5 Conclusion
Chapter 5:General Conclusion and Recommendations
    5.1 General conclusions
    5.2 Recommendations
References
SITUATION OF PAPER PUBLISHED DURING THE MASTER DEGREE PROGRAM
ACKNOWLEDGEMENT



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