液固两相流中二元多尺度BN增强环氧高固厚膜复合材料的冲蚀-磨损耦合损伤行为

Erosion-wear is a general cause of material deterioration of flow-handling components such as impeller, turbine, pump and pipe which work in solid particle-containing corrosive solutions at high flow rates. Particle reinforced polymer composite materials applied as erosion-wear resistant coating draws a lot of attention. Micro/nano-Boron Nitride (BN) materials which own excellent chemically inertness, electrical insulation, thermal conductivity and mechanical properties are very promising erosion-wear determent fillers applied in corrosive slurry. In this project, polyurethane is used to toughen Epoxy resin firstly, then high solid and thick-film Epoxy composite coatings reinforced via Dual and Multi-scale BN particles owning interleaving mosaic structure containing hard wear-resistant phase, friction reduction phase and barrier anticorrosion phase are designed and prepared. We systematically investigate the influences of environmental factors (particle impact velocity, impact angle, time and temperature), and inherent structure of composite coatings ("size effect" and particle size distribution, microstructure, surface hardness, synergistic effect) on the erosion-wear resistance performances of composite coatings. In order to unveil which one play prior role in contributing to the total loss of materials during the whole erosion-wear process, two main effects including mechanical damage and electrochemical corrosion are quantitatively evaluated to identify the synergies or interactions of them. The dynamic evolution of microstructure, crack formation and diffusion of as-prepared composite materials is mainly explored. Microstructure evolution and damage mechanism, the mechanism of the corrosion kinetics, the correlative mechanism between erosion-wear and corrosion of the BN enhanced high solid thick film coatings under the coupling of mechanics and electrochemistry\chemical condition are deeply revealed. The goal of this project is to understand and aid the design and selection of appreciate novel erosion-wear resistant composite materials and technologies for stainless steel moving parts working in high-velocity corrosive slurry.

冲蚀磨损是一种工作在高流速含固体颗粒的腐蚀液体中过流部件，如叶轮、涡轮、泵和管等材料损伤失效的常见形式。氮化硼微/纳材料具有优异的化学惰性、绝缘性、导热性及机械性能，是一类非常有潜力的抗冲蚀磨损填料材料。利用聚氨酯增韧改性环氧树脂，在涂层内部构筑硬质耐磨相、润滑减摩相和阻隔抗蚀相的多维镶嵌交织结构的二元多尺度BN复合协同增强环氧树脂高固厚膜复合材料。系统考察环境因素（磨粒攻角、冲击速度、冲击时间、环境温度）、和涂层特性（“级配效应”以及粒度分布、材料显微组织、表面硬度、“协同效应”）对复合涂层冲蚀磨损性能的影响规律。定量化分析冲刷磨损和电化学腐蚀两个因素在材料冲蚀磨损过程中发挥的作用。重点关注对复合材料内部微观组织结构、冲蚀磨损裂纹形成及扩散的动态过程探索。旨在阐明BN增强高固厚膜涂层在力学-电化学/化学环境耦合作用下的微结构演变和损伤机制、腐蚀动力学规律、冲蚀磨损与腐蚀交互作用规律和机制

海洋钢结构作为海洋设施的重要组成部分，被广泛应用于海洋钻井平台、海上风电设施、跨海大桥和港口工程结构中。然而，由于钢结构缺乏足够的抗冲蚀性能和防腐能力，在复杂的海洋环境中会受到严重的破坏，存在巨大的安全隐患。利用表面改性和纳米复配技术，在涂层内部构筑硬质耐磨相、润滑减摩相和阻隔抗蚀相的多维镶嵌交织结构的二元多尺度BN复合协同增强环氧树脂高固厚膜复合材料。系统考察了涂层特性（“级配效应”以及粒度分布、材料显微组织、表面硬度、“协同效应”）对复合涂层冲蚀磨损性能的影响规律，建立了复合涂层的BN 微/纳颗粒填料的不同尺寸合理级配、含量调控等因素与所制备复合涂料的抗冲刷磨损腐蚀性能之间的“构-效”关系。发现：片层状h-BN提供良好的润滑性能，可以减少对涂层的损伤，而颗粒状c-BN通过提高涂层硬度增强环氧基体，两者协同作用使复合涂层抗冲蚀效果提高56.23%；片层氮化硼在冲蚀过程中在剪切力的作用下层间滑移产生一定的润滑作用，此外球形氮化硼增强了涂层的承载能力，冲蚀过程中可以耗散冲蚀引起的应立集中，纳米填料的加入一定程度上阻碍了裂纹在复合涂层中的扩展，显著提升了复合涂层抗冲蚀性能。初步提出了不锈钢运动部件表面抗冲蚀磨损高固厚膜防护涂层的设计原则。发表科研论文15篇，其中SCI论文13篇，申请发明专利3项。