超临界CO2脉冲电沉积钴基纳米合金薄膜的形成机理、结构控制及摩擦磨损行为研究

本项目将超临界技术与脉冲电沉积技术结合,采用sc-CO2脉冲电沉积制备Co基纳米合金薄膜材料。研究Co基纳米合金薄膜材料在各种sc-CO2脉冲电沉积条件下的形成机理和组织结构特征,研究其组织结构特征对其硬度、与基材结合强度及不同条件下摩擦磨损行为的影响及影响机理，分析Co基纳米合金薄膜在不同条件下的摩擦磨损机理和抗疲劳磨损机制。在此基础上，探讨Co基纳米合金薄膜材料的超临界电沉积条件-组织结构特征-摩擦磨损性能间内在联系，建立其制备工艺-结构-性能的关系模型。最终阐明这些机理和关系，优化sc-CO2脉冲电沉积条件实现Co基纳米合金薄膜的多层梯度结构控制，降低其内热应力，改善其与基体的结合强度和摩擦学性能，揭示sc-CO2在脉冲电沉积过程中的作用机理。本项目的实施对促进超临界电沉积技术和理论的发展及金属薄膜材料摩擦磨损机理的研究都具有重要意义，为制备高性能耐磨薄膜材料提供新方法和理论依据。

By combining supercritical fluid with pulse electrodeposition technology, the project focus on the preparation of nanocrystalline Cobalt (Co) base alloy film by pulse electrodeposition from an emulsified supercritical carbon dioxide (sc-CO2) bath. The formation mechanism and microstructure characteristics of nanocrystalline Co base alloy film deposited under different deposited conditions will be systemically investigated. The influence of the microstructure properties on the hardness, the adhesion strength to the metal substrate, and the friction and wear behavior under different tested condition for the deposited nanocrystalline Co based alloy film will be evaluated. The friction and wear mechanism of the film under different tested condition will be also studied in the project. Based on the study results, the correlation between the deposited conditions of the sc-CO2 assisted-pulse electrodeposition, the microstructure of the prepared Co base alloy film, and the tribological and mechanical property of the film will be discussed to establish the process-structure-property model for the prepared deposit. Eventually, the deposited condition of sc-CO2 assisted-pulse electrodeposition will be optimized to obtain the nanocrystalline Co base alloy film with multi-layered and gradient structure to decrease the internal and thermal stress in the deposits, increase its adhesion strength to the metal substrate, and improve its friction-reducing and anti-wear ability. The conduct of the project has an important significance to develop the sc-CO2 assisted electrodeposition technology and theory and to promote the development of the friction and wear mechanism for metal film materials. Moreover, it will provide a new technology, and its corresponding theory, for the preparation of nanocrystalline alloy film with super anti-wear and mechanical properties.