强韧化高熵合金/陶瓷复合薄膜仿生微结构设计及磨蚀机理研究

With the development of marine economy, damage to parts and components of marine equipment caused by corrosion and wear in seawater environment has become increasingly serious. Toughness and abrasion-resistance integrated surface-modifying coating is the key technology to solve the problem of marine environmental damage. However, the traditional hard protective coating has a common problem of strong brittleness and poor toughness, and it is easy to fail early under the interaction between seawater corrosion and wear. Magnetron sputtering high-entropy alloy film has outstanding wear resistance and corrosion resistance, and has become a surface protection material with great potential in seawater environment. However, the corrosion-wear interaction and damage mechanism of high-entropy alloy films in seawater environment is still unclear, which restricts the development of the tough and abrasion-resistant integrated film based on this new alloy material. This project will systematically study the corrosion-wear interaction and damage behavior of typical high-entropy alloy film in seawater environment, reveal the corrosion-wear physical and chemical properties of high-entropy alloy film in seawater environment, and learn from the structural characteristics such as high hardness, high toughness and corrosion resistance of shells. This is to develop a new type of tough and abrasion-resistant integrated biomimetic nano-multilayer composite film of high-entropy alloy/ceramic, and explore the formation mechanism of bionic nano-multilayer structure as well as the toughness and wear-resistance mechanism of high-entropy alloy, to provide theoretical basis and technical support for the engineering applications of high-entropy alloy films in the marine field.

随着海洋经济发展，海水环境中腐蚀与磨损导致的海洋装备零部件损伤问题日益严重。强韧与耐磨蚀一体化表面改性涂层是解决海洋环境损伤问题的关键技术。然而，传统硬质防护涂层普遍存在脆性强、韧性差的共性问题，极易在海水腐蚀与磨损交互作用下发生早期失效。磁控溅射高熵合金薄膜具有突出的耐磨损和耐腐蚀性能，已成为极具潜力的海水环境表面防护材料。然而，迄今高熵合金薄膜在海水环境中的腐蚀-磨损交互损伤机制仍不明晰，这制约了基于这一新型合金材料的强韧与耐磨蚀一体化薄膜的发展。本项目将系统研究海水环境中典型高熵合金薄膜的腐蚀-磨损交互损伤行为，揭示高熵合金薄膜海水环境腐蚀-磨损的物理化学本质，并借鉴贝壳高硬、高韧和耐腐蚀的结构特性，发展出新型的强韧与耐磨蚀一体化高熵合金/陶瓷仿生纳米多层复合薄膜，探索高熵合金仿生纳米多层结构的形成机制和强韧与耐磨蚀机制，为高熵合金薄膜在海洋领域的工程化应用提供理论依据和技术支持。

为应对海洋国防中海洋装备零部件损伤失效，在该基金资助下，本项目通过强韧与耐磨蚀一体化表面改性高熵合金涂层成分及结构设计，系统的研究了VAlTiCr基高熵合金系列涂层及模拟海洋环境失效机理。首先，从耐海水腐蚀以及材料本征摩擦特性、摩擦界面反应产物对海水润滑耐磨增益的角度筛选调控涂层组分。通过替换或添加不同的合金化元素，制备获得VAlTiCrSi，VAlTiCrSi/C，VAlTiCrCu， VAlTiCrMo，VAlTiCrMo/N，VAlTiCrW，VAlTiCrW/O系列涂层，重点研究了涂层受到化学/电化学所引起的腐蚀以及力学因素所引起的摩擦磨损的交互作用，分析了涂层损伤失效机理，探明了高熵合金涂层在海水介质中腐蚀-磨损交互损伤行为及其微观组织结构对磨蚀性能的影响机制，弥补了现有研究仅独立地考察高熵合金涂层在酸性介质和 NaCl 溶液中的静态电化学腐蚀和摩擦学性能的不足，阐明了海水环境用高性能高熵合金涂层的组分设计准则。进一步，基于高性能强韧与耐磨蚀一体化涂层结构设计方法，发展具有仿生形态的强韧与耐磨蚀一体化高熵合金/陶瓷纳米多层复合涂层体系，制备获得VAlTiCrCu/WC，VAlTiCrCu/VAlTiCrCuN多层涂层，探索出这种高熵合金仿生纳米多层复合涂层的形成机制、强化机制和腐蚀-磨损机制，为高熵合金涂层在海洋领域的工程化应用提供了理论依据和技术支持，这对丰富高熵合金数据资料，发展新型海洋耐磨蚀表面改性涂层材料具有重要意义。最后，基于高熵合金鸡尾酒效应和Erdemir金属氧化物-剪切强度关系，对设计得到的VAlTiCrMo，VAlTiCrCu，VAlTiCrSi，VAlTiCrWOx涂层从成分变化层面考察了涂层大气环境高温摩擦机理及高熵合金摩擦性能变化一致性规律，随后又从高熵合金涂层结构设计出发获得VTiCrMo，VTiCrW，VTiCrMoW单层和VTiCrMo/W多层涂层，进一步验证了设计涂层的力学性能，并考察了涂层的高温摩擦性能。这为涂层的力学、摩擦性能改善提供了指导方向，弥补了高熵合金涂层在高温摩擦方面研究的不足。