WC-CoCr热喷涂过程界面润湿特性及微观机理研究

WC-CoCr coatings were used to wear-resistant and corrosion-resistant protection for aircraft landing gear, turbine machinery and other mechanical industrial parts at the low-medium temperatures, wetting effect and complex reactions in the coating preparation process made the micro structure and organizational complex, resulting in wear corrosion resistance to deterioration or coating failure. Traditional research methods to improve the performance of coating had not been from the view of point of reactive wetting. It was proposed in the project that the wetting properties and interfacial reactions of CoCr/WC system were combined to analyze the coating micro-mechanism. The technology of the online combined analysis and the method of Kinsinger were used. Through the establishment of the kinetic model, reactive wetting characteristics and mass transfer mechanism of the WC/CoCr system was explored, the new method of the interface microscopic mechanism of high temperature spray process was attained. CoCr alloy and WC interfacial reaction wetting mechanism was strengthen, spraying process parameters and component ratios was optimized, the impact of the reactive wetting on coating microstructure and organizations were explored, the regulation of structure and organization of the thermal spray process was achieved. It is expected that the microstructure and structure of the system could be controlled and optimized through this project, theoretical and applied basis will be supposed to improve wear and corrosion resistance of WC-CoCr coating in the field of surface engineering.

WC-CoCr广泛应用于磨损潮湿环境下机械工程部件的表面防护，然而由于喷涂过程的复杂性，喷涂过程中的组织结构变化及物质传输过程缺少相应的研究，涂层性能难以满足实际需求。本项目提出将CoCr/WC体系润湿特性和界面化学反应相结合，对体系在热喷涂过程中的高温瞬时反应润湿机理进行剖析；采用在线联动分析和Kinsinger方法，通过建立动力学反应模型，强化CoCr/WC体系的界面反应润湿机制，探索WC/CoCr体系的反应特性和润湿传质的匹配性规律，获得高温瞬时热喷涂过程界面微观机理研究的新方法；优化高温环境参数和体系物相组分，探索反应润湿性对涂层微观结构和组织的影响规律，阐明反应润湿性对涂层微观结构和组织的调控机理。通过本项目的研究，预期实现对系统微观组织和结构的控制和优化，为机械工业表面工程领域提高WC-CoCr涂层耐磨耐蚀性能提供理论和应用基础。

WC-CoCr广泛应用于磨损潮湿环境下机械工程部件的表面防护，然而由于高温瞬时特性，喷涂过程中涂层的组织结构变化及物质传输过程缺少相应的研究，涂层性能难以满足实际需求。本项目提出将CoCr/WC体系润湿特性和界面化学反应相结合，对体系在热喷涂过程中的高温瞬时反应润湿机理进行剖析；计算了WC-CoCr体系在高温瞬时喷涂过程中的主要生成物相，采用激光加热模拟高温瞬时热喷涂过程, 研究WC-CoCr体系的润湿和反应特性，探索WC/CoCr体系的反应特性和润湿传质的匹配性规律；研究了不同加热功率对WC-CoCr涂层组织结构的影响，结果表明：随着激光加热功率的增加，涂层的组织粗化，脆性增加，主要原因为WC在高温下分解失碳。研究不同粒径WC包覆改性掺杂对WC-CoCr耐磨耐蚀等性能的影响，结果显示，细粒经WC@Co增强了涂层的结合强度和耐磨损性能，由于抗腐蚀性能取决于金属相中的Cr元素，因此，改性后的涂层耐腐蚀性能变化不大。通过本项目的研究，预期实现对系统微观组织和结构的控制和优化，为机械工业表面工程领域提高WC-CoCr涂层耐磨耐蚀性能提供理论和应用基础。