3D打印制备β型Ti-35Nb-2Ta-3Zr合金的微结构演变与力学性能

发布时间：2020-12-31 17:21

　　与现有的传统技术不同,增材制造（AM）技术在制备优异性能的生物医学植入物钛合金上具有巨大的优势。考虑到这一特点,本研究采用了选择性激光烧结（SLS）的方式探究了β型Ti-35Nb-2Ta-3Zr合金的力学性能和微观结构演变。SLS制备的样品中可见沿着柱状晶方向的纵向的扫面路径边界。采用透射电镜表征了之字形型和V-型的{112}<111>β孪晶形成过程以及应力诱发的共生ω结构形成过程。该合金中可见沿着β结构的Ⅰ型孪晶马氏体是变形过程中超塑性和弹性回复的原因。另外,采用高分辨透射电镜观察了在应力集中区,由于[11-1]面的错位引起的β→ω的相变过程。本研究还分析了在沿着纵向孪晶界的弱界面应力区内形成的薄层状ω结构。在应力集中区的β基体两侧边界,存在孪晶引起的ω结构,它是由β-孪晶上的ω-相重叠而形成的。另外,位错缠结和位错塞积沿着马氏体孪晶和应力诱发的ω相产生。最近,β型钛合金的多孔结构由于其低杨氏模量,优异的超弹性和形状记忆效应而显着地发展用于植入物。采用SLS工艺,3D-CAD模型制备了复杂形状的多孔材料,基于不同的孔隙度（0.34%,0.41%和0.48%孔隙率）。通过循... 

【文章来源】：上海交通大学上海市 211工程院校 985工程院校 教育部直属院校

【文章页数】：77 页

【学位级别】：硕士

【文章目录】：
摘要
ABSTRACT
List of abbreviations
Chapter 1-Introduction
    1.1 Introduction
    1.2 Literature review
        1.2.1 Biomaterials
        1.2.2 Types of biomaterial
        1.2.3 Biomaterials' porous structure
    1.3 Development of titanium alloys
        1.3.1 Biomedical titanium alloys
        1.3.2 New generationβ-type titanium alloys
        1.3.3 Biocompatibility of new generationβ-type Ti-35Nb-2Ta-3Zr alloy
        1.3.4 Bone tissue compatibility ofβ-type Ti-35Nb-2Ta-3Zr alloy
        1.3.5 Modulus of elasticity of titanium alloys
    1.4 Additive manufacturing
        1.4.1 Introduction
        1.4.2 Selective laser sintering
        1.4.3 Finishing
        1.4.4 Advantages
    References
Chapter 2-Preparation and experimental method ofβ-type Ti-35Nb-2Ta-3Zr
    2.1 Introduction
        2.1.1 Aim and experimental procedure
    2.2 Material preparation
        2.2.1 Chemical composition
        2.2.2 Material preparation
    2.3 Testing methods
        2.3.1 Mechanical testing methods
    2.4 Microstructure characterization
        2.4.1 Grain morphology analysis
        2.4.2 Phase analysis
        2.4.3 Transmission electron microscopy（TEM）analysis
    Summary
    Reference
Chapter 3-Mechanical properties ofβ-type Ti-35Nb-2Ta-3Zr alloys
    3.1 Introduction
    3.2 Cyclic loading-unloading tensile properties
        3.2.1 Superelasticity of single solid specimen
        3.2.2 Superelastic properties of porous-structures
        3.2.3 Static compression testing
    3.3 Fracture morphology
        3.3.1 Fracture after loading-unloading tensile test
        3.3.2 Fracture after compression test
    Summary
    Reference
Chapter 4-Effect of SLS-process on microstructure and mechanical testing
    4.1 Introduction
    4.2 Grain morphology of SLS-produced specimens
        4.2.1 Microstructure of single solid specimen
        4.2.2 EBSD analysis
        4.2.3 Microstructure of porous specimens
        4.2.4 Grain structure and phase analysis
    4.3 Phase transformation and microstructure evolution
    4.4 Discussion
    Summary
    References
Acknowledgement
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