c-Zr3N4/MeAlN超硬纳米多层膜的断裂行为、红外反射、减振和环境适应性研究

For the compressor blades of aircraft engines with high thrust-weight ratio, the surface temperature can reach 600-800℃, and exhibit faster speed and lighter mass. It is required that protective coating should own superhard, high toughness, good adhesion, high infrared reflection, low thermal conductance and excellent environmental suitability (high thermal stability, oxidation resistance and corrosion resistance), satisfying the strong demand for erosion resistance, heat shielding, vibration damping, oxidation resistance and corrosion resistance. In this work, we will choose cubic c-Zr3N4 with thorium phosphide (Th3P4) structure owing high hardness and extraordinary oxidation resistance as the constituent material, hierarchical constructiion of c-Zr3N4/MeAlN superhard multilayers to satisfy the requirement of these different properties. Focusing on interface problems, the effects of mutual movement of interfaces between columnar grains and between adjacent layers on strengthening and toughening as well as vibration damping should be explored. The facture behavior of multilayers will be investigated by nanoindentation test under different indenter, exploring deformation and fracture mechanism of the multilayers deposited on titanium alloy substrate and evaluating its ability to erosion resistance. Heat treatment under air environment at 800℃ will be performed to study the oxidation process and thermal stability, and electrochemical test under offshore waters environment will be used to investigate the corrosion resistance. In brief, building the relationship between microstructure and each property and obtaining the method to balance these properties by modulating the microstructure are our prime targets, finally, it is expected to design and obtain a multifunctional integrated superhard multilayers for the application on compressor blades of aircraft engines with high thrust-weight ratio.

高推重比发动机压气机叶片的温度达到600-800℃，且具有更快的转速和更轻的质量，这要求保护涂层在中高温条件下（600-800℃）具有超硬高韧、良好附着力、高的红外反射、低热导率和优异环境适应性（高热稳定性、抗氧化性和抗腐蚀性），满足其对抗冲蚀、热屏蔽、减振及高温和海水环境适应性的强烈要求。本项目选用硬度高、化学稳定性好的Th3P4结构c-Zr3N4作为调制层，针对各性能影响的核心因素，分级构建c-Zr3N4/MeAlN多层膜，并围绕界面问题，研究调制层内柱状晶间界面和层间界面运动对多层膜强韧化作用机理及减振的影响；通过纳米压痕方法研究多层膜在不同压头下的断裂行为，探究钛合金上多层膜的断裂机制，评价多层膜抵抗冲蚀的能力；研究800℃空气环境下多层膜的氧化过程及海水环境下薄膜的腐蚀行为，建立各性能的微观作用机理并获得平衡各性能的方法，设计并制备出适用于发动机叶片的多功能一体化新型超硬多层膜。

基于过渡族金属氮/碳化物MeN/C人工周期调制获得的纳米多层膜靠其大量的层间界面通常能现实硬度和韧性的同步提高，因而成为重要的用于发动机叶片及其它机械零部件防护的硬质或超硬涂层。由于其体系的分散性和界面结构的复杂性，基于异构界面的强韧化机理和断裂行为的探索仍是科学关注的重点，同时探索新的纳米结构调控方法并制备出具有环境自适应的新型多功能一体化（以强韧化为核心兼顾环境适应性）的纳米结构涂层是应对当前日益复杂和苛刻应用场景的迫切需求。本项目以多功能一体化防护纳米结构涂层的设计与制备为目标，首先探究了沉积工艺与掺杂/合金化对各调制单层膜（Me(Al) N和Zr3N4）的微结构、强韧化和腐蚀性能的作用规律；其次提出了新的纳米结构调控方法，并构建了多系列富氮Zr3N4/MeAlN（TiAlN/Zr3N4、Ti2AlNbN/Zr3N4和TaN/Zr3N4）及其它（TaN/AlN、TiAlN/MgAl2O4、TaC/Ta、TaC/Ag、TaC/SiC）纳米多层膜，围绕界面问题，探明界面结构支配的强韧化机理、断裂行为、红外反射及在高温或海水环境下的腐蚀行为，为下一代发动机叶片防护用多功能一体化超硬纳米多层膜提供理论基础。研究取得如下进展：1. 基于Nb合金化调控电子结构和构建纳米晶+非晶双相纳米结构引入结晶/非晶异构界面都能实现对TiAlN薄膜的强韧化，此外，适量Mo的引入能激活TaAlN中发生调幅分解进而强韧化; 2. 提出了“贵金属原子固溶”的新策略赋予了MeN防护薄膜更多的环境主动调控能力，实现了强韧、自润滑和输水多功能一体化；3. 构建的2D共格界面TiAlN/Zr3N4纳米多层膜能兼具高硬、高韧、高稳定性、抗氧化、耐蚀和良好的红外反射；4. 提出了“多层沉积”+“驱动结晶/非晶相分离”的全新策略，将传统的2D层状界面拓宽到3D异构界面的调控，获得了新型Ti2AlNbN/Zr3N4三维网格状纳米多层膜，实现了对面内异构界面的构筑；5. 提出“多层沉积”+“固态去润湿”的新路径构建出3D共格界面的TaC@Ta核壳结构纳米复合薄膜，实现超硬/韧化、低摩耐磨、耐腐蚀一体化；6. 项目执行期间，在Acta Mater.、carbon、Surf. Coat. Technol. 等期刊上发表SCI论文37篇、获授权专利5项、毕业博士2名、硕士7名。