钛基非晶生物复合涂层的制备与摩擦磨损行为研究

The poor wear resistance of titanium-based biomaterials has long been a limitation for its stability in human body as orthopedic implants. In this work, we intend to use the high-powered semiconductor laser cladding technology to solve the problem. By controlling thermal cycling and optimizing the related progress parameters, we will fully research and then produce titanium-based amorphous bio-coatings with extremely high wear resistance. We will focus our attentions mainly on the following aspects. First, through the numerical simulations and infrared thermal imaging observations, we will establish a mathematical model between the input energy of laser, cooling conditions and the temperature field as well as the thermal cycling of the molten pool.Second, we aim to reveal how the temperature field and the thermal cycling of the molten pool can make an effect on the proportion of amorphous components in the coating and the interface between amorphous and crystallized components. Third, it is also important to study the tribological behavior of the various amorphous/crystal morphology coatings under different conditions. Besides, an analysis of their underlying wear mechanism is required. Fourth, we will work out the functional model which can illuminate the relativity between mechanical properties of the titanium-based amorphous composite coating and its wear behavior. Over all, in this work, an attempt has been made to work out the problem of the poor wear resistance of titanium-based orthopedic implants, to get a better comprehension of the tribological behavior of amorphous composite coatings, to consummate the theoretical knowledge system of metallic glass materials and to promote the practical use of amorphous composite coatings.

钛合金人工关节植入件的耐磨性差一直是长期困扰其稳定应用的难题，本项目拟采用高功率半导体激光熔覆技术，通过控制热循环和工艺优化，制备并研究钛基非晶耐磨生物涂层。主要研究以下内容：第一，通过数值模拟及红外热成像观测，建立激光能量输入及冷却条件与熔池温度场、热循环关系的数理模型；第二，揭示熔池温度场、热循环对非晶比例分数、非晶/晶体界面特征的影响规律；第三，研究不同工况下，各种非晶/晶体组织形态涂层的摩擦磨损行为，并阐明其潜在磨损机理。第四，研究钛基非晶复合涂层力学性能与摩擦磨损行为的相关性，并建立相应的函数模型。通过本课题工作，能够解决钛合金人工关节件耐磨性差的难题，加深对非晶复合涂层摩擦磨损行为的认识，完善非晶合金知识理论体系，促进非晶复合涂层实用化。

钛合金具备高比强度、耐腐蚀性和生物相容性等优异性能，一直是金属生物材料研究的热点。钛合金人工关节植入件的耐磨性差一直是长期困扰其稳定应用的难题，本研究通过采用高功率半导体激光熔覆技术，调控设计合金成分，控制热循环和工艺优化，制备并研究钛基非晶耐磨生物涂层。同时，针对钛合金缺乏生物活性，弹性模量过高等问题，本研究选取镁、钽、钼作为合金元素，制备出一系列用于骨组织修复和替换的新型生物医用钛合金。所取得的创新性成果如下：.(1)采用激光熔覆制备出具有良好生物相容性的Ti45Cu41Ni9Zr5和Ti45Cu41Ni6Zr5Sn3（at.%）非晶复合涂层，其耐磨性能明显优于Ti-30Nb-5Ta-7Zr（wt.%）基体。.(2)通过混料-压制-烧结的传统粉末冶金方法制备Ti-Ta二元粉末冶金材料。所制备的Ti-Ta合金具有很高的抗拉强度（>1000 MPa）和较低的弹性模量，同时具有良好的生物相容性。.(3)采用机械合金化和放电等离子烧结相结合的工艺制备了生物相容性优良的Ti-Mg合金，其压缩弹性模量为36-50 GPa，抗压强度为1500-1800 MPa。.(4)采用熔炼方法制备Ti-Mo合金，并深入探讨了不同（3.2-12 at.%）Mo含量合金显微组织与力学性能的相关性。.通过本项目研究，在国内外知名期刊，如Materials Characterization，Materials Science and Engineering C，Journal of the mechanical behavior of biomedical materials等，发表学术论文10篇，申请发明专利5项，其中已授权2项，培养硕士研究生3名。参加国内外学术会议，并做口头报告5次，与新加坡南洋理工大学建立了长期合作关系。