镁合金骨植入材料在葡萄糖与多因素耦合下剥蚀机理研究

我国高血糖和糖尿病患者高发和镁合金剥蚀的发现提示镁合金骨植入材料发展面临新挑战。然而，镁合金剥蚀机制尚不清楚。本项目拟利用现代表面表征技术如EBSD、原位TEM、微区电化学分析和自制压应力电化学腐蚀装置，研究镁合金在压应力下微结构及塑性变形机制、微区电化学电位分布及动力学特征，揭示其在含葡萄糖等有机分子模拟液中的剥蚀机理；通过热处理、微弧氧化处理，调控其组织和耐蚀性能，建立挤压态镁合金微观组织、电化学特征、腐蚀产物、应力与剥蚀的关系，提出镁合金剥蚀机制和防护措施；采用分子动力模拟和表面表征方法，探究镁合金及微弧氧化膜在含葡萄糖及蛋白质的人体模拟体液中剥蚀行为，分析葡萄糖、蛋白质及其耦合的构象演化、吸附行为、腐蚀行为等关键因素，建立表面有机分子吸附对镁合金腐蚀特性和生物相容性机理模型；比较在体和体外腐蚀试验结果，从多因素、多层次理解剥蚀机理，促进腐蚀学科的发展。该项目有重要的理论和临床意义。

In view of the hyperglycemia and high incidence of diabetes in our country, and the finding of exfoliation corrosion on magnesium alloy, the development of degradable magnesium alloy bone implants faces novel challenges. However, the exfoliation mechanism remains unclear. This project intends to use advanced surface characterization techniques such as EBSD, in-situ TEM, micro-area electrochemical analysis and self-made compressive stress electrochemical corrosion device to study the microstructure and plastic deformation mechanism of magnesium alloy under compressive stress, and micro-area electrochemical potential distribution and dynamic characteristics. This project focuses on revealing the mechanism of exfoliation corrosion of magnesium alloy in simulated body fluids containing glucose organic molecules. Through heat treatment and micro-arc oxidation treatment, the structure and corrosion resistance are adjusted. The relationship between microstructure, electrochemical characteristics, corrosion product as well as stress with exfoliation corrosion of the extruded magnesium alloy will be established. The formation mechanism of exfoliation corrosion and protective measures of magnesium alloy are proposed. The molecular dynamics simulation and surface characterization methods are adopted to explore the exfoliation corrosion behavior of magnesium alloy and micro-arc oxidation film in simulated body fluid containing glucose and protein. The key factors such as conformational evolution, adsorption behavior, and corrosion behavior of glucose, proteins and their couplings are used to establish the model of the corrosion characteristics and biocompatibility mechanism of magnesium alloys adsorbed on the surface by organic molecules. The in vivo and in vitro corrosion test results will be compared. The mechanism of exfoliation corrosion of magnesium can be understood from multiple factors and multi-level. This project can promote the development of corrosion discipline. The project has important theoretical and clinical practical significance.