摘要镍钛合金是典型的形状记忆合金，作为生物医用金属材料之一，有着很高的机械强度和抗疲劳特性，但由于其本身的生物活性不满足生物体的需求,成为其应用发展中着力研究的热点。同时，羟基磷灰石(HA)因其高的生物相容性和生物降解性而成为具有代表性的生物活性材料，在近代生物医学工程学科领域受到人们密切关注，可是又由于它是陶瓷相，强度不足脆性大成为限制其发展的主要因素。那么前者和后者的结合成为必然趋势。在镍钛合金表面制备羟基磷灰石生物涂层便可以扬长避短，不仅保留了优异的力学性能又获得了良好的生物活性，因此这种结合方式为硬组织材料的应用前景打开了更开阔的视野。本论文中即将采用激光熔覆技术在镍钛合金表面熔覆羟基磷灰石与钛粉复合涂层，用X射线衍射仪和扫描电镜分析熔覆层的物相和组织结构。结果表明，用激光熔覆技术可以在镍钛合金的表面得到含有羟基磷灰石的熔覆涂层。同时针对激光熔覆工艺参数对涂层的影响也进行了探究。研究表明，影响激光熔覆的因素主要有激光功率和扫描速度。此外，还进行了模拟体液浸泡的实验，探究陶瓷涂层的生物活性。10190
关键词：镍钛合金   羟基磷灰石   激光熔覆  生物陶瓷涂层毕业设计说明书（论文）外文摘要
Title  The study of laser cladding Ti/HA composite       coating on the surface of NiTi alloy.  
Abstract
Nickel titanium alloy is typical of the shape memory alloy. It has high mechanical strength and anti-fatigue properties, so it was used as a biomedical metal materials. However, due to its bad biological activities which is far from the demand of living organisms, this issue becomes a hot spot on the field of the application development research. The high biocompatibility and biodegradability of Hydroxyapatite(HA)drive it into a representative of the biological activity material, which enables  people to pay much attention to the fields of modern biomedical engineering. But it is a ceramic phase,its low strength and brittleness  become the main factors to limit its development. Therefore, the combination of the both materials is inevitable. Preparation of hydroxyapatite biological coating on the surface of the NiTi substrate can synthesize their advantages and abolish their disadvantages .It not only retains the excellent mechanical properties but also gains the good biological activity , so this combination method broaden the  horizons for the prospect of hard tissue material. In this paper,we will prepare Ti/HA composite coating on the surface of NiTi alloy using laser cladding technology,and analyse composition and organizational structure of the cladding layer material by using X-ray diffraction and scanning electron microscopy. Results show that obtaining hydroxyapatite coating on the surface of NiTi alloy is prospective by laser cladding technology.Both the scanning speed and laser power attach to laser cladding parameters are also exploring for the influence on coatings.In addition, the SBF immersing experiment of the ceramic coating is used to explore the biological activity.
Keywords:  Nickel Titanium alloy    Hydroxyapatite     Laser cladding    bio-ceramic coating
目   次
1  引言    1
1．1  镍钛合金    1
1.1.1  镍钛合金的组成    2
1.1.2  镍钛合金的性能    3
1.1.3  镍钛合金的生物相容性    4
1.1.4  镍钛合金的表面改性    5
1．2  Ti/HA复合材料    6
1.2.1  羟基磷灰石    6
1.2.2  HA /Ti复合材料    7 NiTi合金表面激光熔覆TiHA复合涂层的研究:http://www.751com.cn/cailiao/lunwen_9173.html