與現(xiàn)有的傳統(tǒng)技術(shù)不同,增材制造（AM）技術(shù)在制備優(yōu)異性能的生物醫(yī)學(xué)植入物鈦合金上具有巨大的優(yōu)勢�？紤]到這一特點,本研究采用了選擇性激光燒結(jié)（SLS）的方式探究了β型Ti-35Nb-2Ta-3Zr合金的力學(xué)性能和微觀結(jié)構(gòu)演變。SLS制備的樣品中可見沿著柱狀晶方向的縱向的掃面路徑邊界。采用透射電鏡表征了之字形型和V-型的{112}<111>β孿晶形成過程以及應(yīng)力誘發(fā)的共生ω結(jié)構(gòu)形成過程。該合金中可見沿著β結(jié)構(gòu)的Ⅰ型孿晶馬氏體是變形過程中超塑性和彈性回復(fù)的原因。另外,采用高分辨透射電鏡觀察了在應(yīng)力集中區(qū),由于[11-1]面的錯位引起的β→ω的相變過程。本研究還分析了在沿著縱向?qū)\晶界的弱界面應(yīng)力區(qū)內(nèi)形成的薄層狀ω結(jié)構(gòu)。在應(yīng)力集中區(qū)的β基體兩側(cè)邊界,存在孿晶引起的ω結(jié)構(gòu),它是由β-孿晶上的ω-相重疊而形成的。另外,位錯纏結(jié)和位錯塞積沿著馬氏體孿晶和應(yīng)力誘發(fā)的ω相產(chǎn)生。最近,β型鈦合金的多孔結(jié)構(gòu)由于其低楊氏模量,優(yōu)異的超彈性和形狀記憶效應(yīng)而顯著地發(fā)展用于植入物。采用SLS工藝,3D-CAD模型制備了復(fù)雜形狀的多孔材料,基于不同的孔隙度（0.34%,0.41%和0.48%孔隙率）。通過循... 

【文章來源】：上海交通大學(xué)上海市 211工程院校 985工程院校 教育部直屬院校

【文章頁數(shù)】：77 頁

【學(xué)位級別】：碩士

【文章目錄】：
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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