【作者】 戴采云；

【导师】 张亚平；

【作者基本信息】 重庆大学 ， 材料学， 2003， 硕士

【摘要】 生物材料是近年来发展非常迅速的重要功能材料之一，包括生物金属、生物陶瓷材料和生物高分子材料等。在医用金属材料表面形成一层生物陶瓷是制备高性能、高可靠性生物植入材料的有效途经。它既避免了金属材料无生物活性、易腐蚀的问题，又能克服生物陶瓷材料力学性能差的缺陷，并已得到广泛应用。本课题组在国内外首次采用激光处理技术制备了在TC4(Ti6Al4V)钛合金表面同步合成及熔覆以羟基磷灰石(HA)为主的生物陶瓷涂层复合材料。对于这种层状生物复合材料而言，界面是比较重要的部分，其性能的好坏直接决定着整个材料的质量和寿命。所以本文针对这种情况，采用实验、数学计算以及计算机数值模拟等方法较深入地研究了激光熔覆生物陶瓷涂层的界面状况；并且对涂层中加入稀土Y2O3的作用进行了分析。本文首先采用实验手段，对界面的组织形貌、成分、物相及显微硬度等进行了研究。发现加入稀土Y2O3可有效控制其界面两侧原子的短程扩散及界面反应的发生，改善其界面组织结构，从而提高结合强度。其次，通过计算机数值模拟技术，采用计算机辅助工程软件ANSYS6.1对激光熔覆生物陶瓷涂层的界面进行了温度场及应力场模拟，得到激光熔覆材料冷却到室温后其界面的残余应力分布以及位移分布。其结果是，界面在经过搭接熔覆后部分纵向应力为拉应力，但数值远小于界面的结合强度，所以界面的质量不会受到影响。再有从热力学计算的角度分析了在模拟温度场的加热温度条件下涂层及界面可能发生的反应。数学计算表明，在该实验条件下，涂层不仅完全具备合成羟基磷灰石、磷酸钙等生物陶瓷的热力学条件，而且也满足界面化学反应生成钛酸钙等新相的条件。它们均已被X-ray物相分析所证实。最后对数值模拟温度场、残余应力场及热力学计算进行了验证，对本文所得结果进行了分析讨论。更多还原

【Abstract】 Biomaterial is one of the most important functional materials that develop very fast in these days. Biomaterials include bimetals, bio- ceramics, and bio-macromolecule materials and etc. It is an effective method to create well-performing and highly dependable biomaterial that coats a bed of bio-ceramic on metals. The method can not only avoid the erosion of the bimetal but also avoid the bad dynamic capability of bio-ceramic. So the bio-composite material is used more and more widely. The interface of bio-composite material is a very important section. It will affect the quality and life of the total material. The interface is related to the bonding strength and dilution. According to the practice of bio-ceramic coating material, this paper has studied the status, temperature field and stress field of interface.First, the interfacial structure, components, substances and rigidity are researched through experiments. The experiment find that the adding of RE can effectively control the short distance diffuse and the happen of interfacial reactions. The result is the interfacial structure has been improved and the bonding strength has been increased.Secondly, the temperature field, stress field and displacement field are analyzed by means of computer numerical simulation. The result is that the uprightness stress is positive on the interface. But the final value of the strength is lower than that of the bonding strength. So the quality of interface can’t be influenced.Then, with the result of computer numerical simulation used, the free energy of reactions is computed. The result is that the free energy is negative under the condition of laser heating. So there are many new substances that are made. X-ray has proved these substances.Finally, it is validated that temperature field, residual stress field and thermodynamic calculation. The results are analyzed and discussed.更多还原