激光直接沉积制备生物骨材料研究

发布时间：2018-07-27 18:45

【摘要】：全球人口的增长以及人口老龄化趋势的增大,还有交通、自然灾害等意外事故的频频发生,骨骼移植或者替换需求量与日俱增。在人们已经研究出的各种生物骨材料中,金属以及金属基生物材料凭借优良的力学性能,在临床植入领域受到广泛的青睐。近年来,随着激光直接沉积成形技术的发展,利用激光直接沉积成形方法制备生物骨材料成为了前沿性研究课题之一。钛合金、钴铬合金因具有生物骨材料的基本特性,成为激光表面处理与直接沉积成形研究的重要材料。本研究利用半导体激光器采用激光直接沉积技术制备了以TC4为基体的Ti基生物骨涂层和Co-Cr基生物骨涂层以及在Q235钢板上沉积成形制备了高厚层钴铬复合材料,采用金相、扫描电镜、透射电镜、XRD、硬度、摩擦磨损和电化学等分析手段,对实验制备的样品的组织结构、性能及其制备机理等进行了系统研究。研究结果表明：Ti基生物骨涂层优化后的沉积工艺参数为,功率1500W、扫描速度300mm/min、光斑尺寸7.18mm×4.30mm,该工艺参数制备的梯度涂层开裂情况最小。涂层顶部陶瓷区组织疏松,有孔隙均匀分布于表面,有利于骨组织的长入；涂层中含有HA、CaTiO3、 Ca3(PO4)2等生物陶瓷相存在,涂层顶部硬度高达1900HV。Co-Cr基生物骨梯度涂层优化出的沉积工艺参数为,优化功率1400W,扫描速度440mm/min,光斑尺寸7.6mm×4.5mm,第二梯度层中Zr02的优化含量为2%,第三梯度层中Zr02优化含量为3%,梯度涂层厚达3mm左右,具有良好的强韧性；涂层中主要含有CaTiO3、Co2Ti4O和Ti03等生物陶瓷相,涂层顶部硬度可达1500HV左右。激光直接沉积成形制备出了厚度达到7mm的钴铬复合生物材料,发现Y203加入具有消除激光成形裂纹、影响α-Co和ε-Co之间的转变和细化组织的明显作用。当添加2wt.%的Y203时成功消除了沉积层中的裂纹,材料的硬度达到450HV,具有良好的耐磨性能；制备的三种Y203含量钴铬生物复合材料样品在酸性口腔环境中的耐蚀性均高于中性环境中的耐蚀性,且2wt.%Y2O3含量样品的腐蚀速率在两种环境中均最低。
[Abstract]:The global population growth and population aging trend, as well as traffic, natural disasters and other accidents, the need for bone transplantation or replacement is increasing. Among all kinds of biomaterials, metal and metal-based biomaterials have been widely used in the field of clinical implantation due to their excellent mechanical properties. In recent years, with the development of laser direct deposition technology, the preparation of biomaterials by laser direct deposition has become one of the leading research topics. Titanium alloy and cobalt-chromium alloy have become important materials for laser surface treatment and direct deposition because of their basic properties of biomaterials. In this study, Ti based biological bone coatings and Co-Cr based biological bone coatings based on TC4 were prepared by laser diode direct deposition technique, and high thick cobalt chromium composite materials were fabricated by deposition on Q235 steel sheet. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), hardness, friction and wear and electrochemical analysis were used to study the microstructure, properties and preparation mechanism of the samples. The results show that the optimized deposition process parameters are: power 1500W, scanning speed 300mm / min, spot size 7.18mm 脳 4.30mm. The microstructure of the ceramic area at the top of the coating is loose and the pores are uniformly distributed on the surface, which is beneficial to the growth of bone tissue, and there are some bioceramics, such as HAC CaTiO _ 3, Ca3 (PO4) _ 2, in the coating. The optimized deposition process parameters of the top hardness of the coating up to 1900HV.Co-Cr based biological bone gradient coating are, The optimized power is 1400W, the scanning speed is 440 mm / min, the spot size is 7.6mm 脳 4.5mm, the optimized content of Zr02 in the second gradient layer is 2, the optimized content of Zr02 in the third gradient layer is 3 and the thickness of the gradient coating is about 3mm, it has good strength and toughness. The coating mainly contains CaTiO3Co2Ti4O and Ti03 bioceramics, and the top hardness of the coating is about 1500HV. Co-Cr composite biomaterials with thickness up to 7mm were prepared by laser direct deposition. It was found that Y203 could eliminate laser forming cracks, influence the transformation between 伪 -Co and 蔚 -Co and refine the microstructure. When 2wt.% Y203 was added, the cracks in the deposit layer were successfully eliminated, the hardness of the material reached 450 HVV, and the material had good wear resistance. The corrosion resistance of the three kinds of cobalt-chromium biocomposites with Y203 content in acidic oral environment was higher than that in neutral environment, and the corrosion rate of 2wt.%Y2O3 content samples was the lowest in both environments.
【学位授予单位】：东北大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：R318.08

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