钝化体系中表面梯度改性层在腐蚀-磨损协同作用下的失效机理研究

Common self-passivation metals have high corrosion resistance but low contact loading capacity and inferior wear resistance. A rational selection of the gradient modified layer is helpful to improve the wear and corrosive wear resistance of metals in a passivation corrosion medium and retaining its corrosion resistance. A comparative study on wear and corrosive wear synergistic behavior of modified and unmodified self-passivation metals was conducted by an improved online tribo-electrochemical noise measurement. The relationship between the microstructure and activated state of the wear track on the surface of the material will be investigated. The microstructure, recovery rate and corrosive wear process evaluation law of the re-passivation layer in typical contact area and its invalid behavior in corrosive wear will be studied for the surface gradient modified layer. In the formation process of the re-passivation layer, combined the analysis on the phase components of the electrolyte liquid and surface material, the typical phase structure, gradient composition and repassivation layer formation kinetic equations will be obtained, and it will be clarified for the correlation between the impedance of cathode and anode electrochemical processes with different surface composition and surface microstructure of composite. Accordingly, the gradient composition will be quantitatively or semi-quantitatively corresponding with the corrosive wear behavior. The study on synergistic attack of corrosion and wear of the modified layer of typical self-passivation metal surfaces provides gudance to the design and life prediction for the gradient modified layer on the surface of material in the passivation conditions.

针对常见自钝化耐蚀金属表面承载能力低、耐磨性差的问题，在兼顾原有耐蚀特性的前提下，合理选择表面梯度改性层改善金属材料在钝化介质体系中的磨损及腐蚀-磨损抗力。借助改进的摩擦-电化学噪声在线测试方法，研究自钝化金属改性前后的磨损、腐蚀及腐蚀-磨损协同行为，探讨表面梯度改性层摩擦接触部位的组织结构及其与活化状态间的关系，了解再钝化层的组织结构与恢复速率及其在腐蚀-磨损过程中的作用；结合电解质液相组分以及表面物相分析，确定典型接触表面物相、梯度成分及其钝化层生成动力学方程，澄清钝化体系中表面阴极和阳极电化学过程中的复合阻抗与表面组织结构间的关联问题，提出表面梯度组织成分与腐蚀-磨损性能间的对应关系，并做出定量或半定量表述。通过对表面梯度改性层的腐蚀-磨损协同损伤机理的研究，将可为典型钝化体系中腐蚀-磨损耦合损伤的表面梯度防护层设计及其安全使役提供参考。

采用表面改性技术（等离子表面冶金技术、磁控溅射、电化学沉积等）在常见自钝化金属表面制备了表面改性层。借助改进的摩擦-电化学噪声在线测试方法，研究了自钝化金属改性前后的磨损、腐蚀及腐蚀-磨损协同行为，确定了典型接触表面物相、梯度成分及其钝化层生成动力学方程。 澄清了钝化体系中表面阴极和阳极电化学过程中的复合阻抗与表面组织结构间的关系，确定了表面梯度组织成分与腐蚀-磨损性能间的对应关系，并做出了定量或半定量表述。采用电化学噪声技术监测改性前后的常见自钝化耐蚀金属在浸泡过程的腐蚀行为，确定了表面物相、成分与腐蚀机理的关系。借助纳米压入及微米压入实现了对纯钛表面钼梯度改性层力学性能参数的定量表征，结合有限元数值模拟，建立了改性层塑性性能参数的反演分析方案。此外，还对改性前后的自钝化耐蚀金属的生化特性开展了研究。项目研究结果，可为常见自钝化金属的表面改性层设计及其应用提供理论参考。