低毒性钛基非晶合金复合材料的制备、机械性能及生物活性研究

In this proposal, the fabrication, mechanical properties and bioactivity of novel non-toxic Ti-based bulk metallic glassy composites are going to be investigated. The mother alloys are prepared by arc melting of pure non-toxic metals. Then the ribbon and bulk samples are to be fabricated by melt-spinning and copper mold casting. The in-situ composites are obtained by the addition of special elements or heat-treatment of the as-cast samples at the temperature between the temperature of glass transformation and onset crystallization temperature. The ex-situ composites are prepared by directly adding the oxide or metal powder in nano scale. The microstructure, thermal stability and mechanical properties are studied, respectively. The mechanism of the effect of second phased on the mechanical properties of Ti-based bulk metallic glasses is to be discussed. On the other hand, the bioactivity of the Ti-based bulk metallic glassy composites is studied by electrochemical-hydrothermal treatment and pre-calcification treatment, following by the immersion in simulated body fluid. The effect of current density, temperature, and treating time on the microstructure and composition will be discussed. It is expect that the porous surface enriched with Ti will formed on the surface of bulk metallic glassy composites after electrochemical-hydrothermal treatment. The pre-calcification process will accelerate the nuclear of calcium phosphate. Finally the bone-like apatite is formed on the pretreated surface after immersion in simulated body fluid.The cytotoxicity and implant of the Ti-based bulk metallic glassy composites testing are also to be explored. The research is beneficial to develop Ti-based bulk metallic glassy matrix composites, accelerate the application of non-toxic Ti-based metallic glassy composites with excellent bioactivity and good mechanical properties in biomedical fields.

本项目主要开展低毒性钛基非晶合金复合材料的制备、机械性能及生物活性研究，最终目标是获得低毒性、低模量、高塑性及高生物活性的新一代钛基非晶生物材料。为了解决非晶合金的脆性问题，通过原位生成纳米晶及添加纳米晶第二相的方式获得具有良好综合机械性能的复合材料，并探讨第二相改善非晶合金机械性能的机制。同时研究该复合材料表面活化方法、细胞毒性及骨结合性。具体采用电化学水热处理法及预钙化法相结合的方式，提高表面的粗糙度和钛含量；分析电流密度、处理时间、温度以及溶液种类和浓度对表面成分和形貌的影响；最终形成与人体骨组织的结构和成分相似的羟基磷灰石多孔表面，并探讨其形成机制；最后对该复合材料的细胞毒性与植入试验进行研究。该项目对于丰富钛基非晶合金复合材料的制备、机械性能的改善及生物活性处理技术的发展，实现具有综合优异机械性能和良好生物活性的低毒性钛基非晶合金复合材料的实际应用具有重要意义。

非晶合金因其组织结构和成分的均匀性,而具有优异的力学性能,耐腐蚀性能和生物活性,有望应用于生物医疗领域。本项目着重研究了新型低毒性钛基非晶合金及其纳米晶复合材料的机械性能,电化学腐蚀行为和生物活性，调查了微量添加元素Nb，Ta，Au，Pt对其微观组织及力学行为和电化学腐蚀行为的影响。明确了成分变化导致的内生纳米晶相对微观组织及力学行为变化的作用机制，阐明了非晶合金表现出高耐腐蚀性能的内在机理。此外本项目探索研究了钛同族元素锆基非晶合金作为生物医用材料的相关性能，研究了元素Nb的添加对Zr基非晶合金微观结构、力学性能、电化学腐蚀行为及细胞毒性的影响，发现Nb元素可改善Zr基非晶合金的力学性能，有效提高其耐腐蚀能力同时降低细胞毒性，提高细胞繁殖能力。本项目从成分设计入手，研究成分、微观结构、力学性能、电化学性能及生物活性之间的关系，拓展了非晶合金的应用领域。