人工关节植入体运动和固定界面的生物摩擦腐蚀耦合行为研究

The friction and corrosion in biological environment have become the key technical problems to affect the service life and reliability of the artificial joint implants. Due to the complexity of the human body environment, the friction and corrosion will effect on the artificial joint frictional pairs in synergistic effects. Independent studies on the biotribology or corrosion behaviors are difficult to reveal the key problem of the failure for the artificial joints. Therefore, the investigation on the coupling mechanisms of the biotribology and corrosion behaviors of the artificial joints has the important theory and application values. In this project, the typical artificial joint combinations are selected to study the coupling mechanisms of the biotribology and corrosion for the moving and fixed interfaces of the artificial joint implants. The theory of the bio-tribocorrosion for the artificial joints will be established in this study. In the conditions of the simulated human body biological environments, the producing mechanism of the wear debris will be analyzed on the coupling effects of the biotribology and corrosion. On the basis of the effective characterization of wear debris and establishment of the related model, the generating mechanism of the wear debris of the artificial joints will be put forward. The influence of the bio-tribocorrosion conditions and biological lubricating medium on the metal ion release behaviors will be investigated in all directions. The objective is to improve the evaluating technology of the bio-tribocorrosion for the artificial joints. These research works will provide the technical supports for the evaluation of the reliability system for the artificial joints and the important experimental and theoretical basis for the design and manufacture of the high-performance artificial joint implants.

生物摩擦和腐蚀已成为影响人工关节植入体服役寿命和使用可靠性的关键技术问题，由于人体环境的复杂性，摩擦和腐蚀将协同作用于人工关节摩擦副，而独立的生物摩擦学或腐蚀行为研究，难以揭示人工关节的失效本质问题。因此，对人工关节植入体的生物摩擦腐蚀耦合作用机理的研究具有很高的理论和应用价值。本项目将以典型人工关节摩擦副为研究对象，研究人工关节摩擦副的生物摩擦腐蚀机理，建立人工关节生物摩擦腐蚀失效的基本理论；在模拟人体生物环境条件下，分析摩擦和腐蚀协同作用的磨粒产生的机理，并对磨粒进行有效表征，建立相关数学模型，提出并完善人工关节磨损颗粒的产生机制。综合研究摩擦腐蚀条件和生物润滑介质等对金属离子释放的影响规律，完善人工关节的生物摩擦腐蚀综合评价技术。通过上述研究工作，为人工关节的可靠性系统评估提供技术支持，并为高性能人工关节植入体的设计与制造提供重要的实验和理论依据。

本项目研究了人工假体金属材料的运动和固定界面的摩擦腐蚀行为。基于人工关节生物摩擦腐蚀实验平台及数据采集系统的设计，建立了体外摩擦腐蚀模拟实验方法，综合评价了金属假体材料的摩擦腐蚀性能，系统分析了人工关节金属材料的运动和固定界面的摩擦腐蚀机理，阐明了摩擦腐蚀运动体系中磨损腐蚀损耗(Wtot)与机械磨损(Wwear)、腐蚀损耗(Wcorr)和摩擦腐蚀耦合作用损耗(Wcoup)等的相互关系。综合摩擦腐蚀运动有限元和不同磨损体系的摩擦腐蚀运行状态研究，分析了假体材料运动界面和固定界面的摩擦腐蚀磨损失效机制，建立了摩擦腐蚀耦合作用机理模型，为人工关节材料摩擦腐蚀失效研究奠定了理论基础。以改进雷达图分形技术为基础，结合摩擦学分形理论，研发了磨粒轮廓自动提取与分形识别系统，实现了摩擦腐蚀系统单个磨粒和磨粒群体的形貌提取、分形维数计算和磨粒参数统计，建立摩擦与腐蚀耦合作用的人工关节磨损颗粒的产生机制，为人工关节磨粒的识别和诊断提供了新的数字化分析系统。研究了运动和微动摩擦腐蚀条件下人工关节金属离子的释放行为，结合摩擦腐蚀的耦合作用和磨损颗粒的生成机制，分析了摩擦腐蚀金属离子产生机理，构建了摩擦腐蚀过程中金属离子释放的交互作用模型。基于人体天然关节的骨-软骨-骨的配副形式，利用化学交联法在超高分子量聚乙烯关节窝表面制备了仿生软骨层，提出人工关节运动界面的软垫式结构设计。结合仿生关节软骨摩擦接触有限元模型分析，建立了仿生关节软骨摩擦性能与液体承载的关系，为实现人工关节运动界面的软体设计奠定了技术基础。