磁控溅射高熵合金薄膜的氮化改性及其高温摩擦学行为研究

High-entropy alloys and high-entropy alloy films present the excellent comprehensive properties, such as high hardness, high strength, good wear-resistance and good corrosion-resistance, so that they possess a high research value and broad application prospect, and have been becoming one of research hotspots in the field of materials science. However, compared to the conventional film systems, the research on high entropy alloy films is a late start, leading to the obvious lack of researches on the phase formation mechanism, composite modification treatment, high-temperature tribology behavior and other aspects, which still needs more extensive and in-depth exploration in the experimental research and theoretical analysis. In this project, AlCrTiV-X (X=Si, Cu, Zr, W, Mo, etc.) nitrided high-entropy alloy films will be prepared by combining the technologies of PVD (magnetron sputtering) and plasma-nitriding modification. The effect of type and content of component elements X, and parameters of magnetron sputtering and nitriding modification on the microstructure of nitrided high-entropy alloy films will be studied, in order to reveal the phase formation mechanism and nitriding modification mechanism of nitrided high-entropy alloy films, and the high-temperature tribological behavior of nitrided high-entropy alloy films will be investigated in detail, in order to clarify the high-temperature friction and wear mechanism. Based on this project, it will provide basic data and technical support for broadening and accelerating the application of high-entropy alloy films in the field of high-temperature friction and wear.

由于高熵合金及其薄膜展现出了优异的综合性能，如高硬度、高强度、良好的耐磨性和耐蚀性，导致其具有很高的研究价值和广阔的应用前景并正成为材料科学领域的一大研究热点。然而相比于传统薄膜体系，高熵合金薄膜的研究起步较晚，在诸如相形成机制、复合改性处理、高温摩擦学行为等方面的研究明显不够，仍需在实验研究和理论分析方面进行更为广泛而深入的探索。本项目耦合磁控溅射PVD技术和等离子氮化改性技术来制备AlCrTiV-X(X=Si、Cu、Zr、W、Mo等)氮化高熵合金薄膜，研究X主元元素种类和含量、磁控溅射工艺参数及等离子氮化改性工艺参数对氮化高熵合金薄膜组织的影响规律，揭示其相形成机制及氮化改性机理，并系统考察氮化高熵合金薄膜的高温摩擦学行为，明确其高温摩擦磨损机理，为拓宽和加速高熵合金薄膜在高温摩擦磨损领域的应用提供基础数据和技术支撑。

为丰富和扩宽高熵合金薄膜的基础研究，在该基金的资助下，本项目系统开展了AlCrTiV-X高熵合金薄膜的磁控溅射制备和后续氮化改性及其摩擦学相关基础研究。基于磁控溅射拼靶设计，通过改变X主元元素制备了一系列AlCrTiV、AlCrTiVSi、AlCrTiVCu、AlCrTiVMo和AlCrTiVCuMo高熵合金薄膜，重点研究了镀膜偏压、镀膜温度及X主元元素对高熵合金薄膜组织和性能的影响，实现了高熵合金薄膜的磁控溅射可控制备并揭示了AlCrTiV-X高熵合金薄膜的磁控溅射相形成机制；基于磁控溅射氮化和等离子氮化两种手段，制备了AlCrTiVMo-N、AlCrTiV-N、AlCrTiVSi-N氮化高熵合金薄膜，实现其硬度和耐磨性的大幅提升，并通过对比研究明确了其氮化改性机制。针对高熵合金薄膜高温摩擦学研究的不足，重点研究了高温热处理对AlCrTiVSi高熵合金薄膜组织和高温摩擦学性能的影响；通过研究高温下的显微组织演变规律，明确了AlCrTiVSi高熵合金薄膜在700℃下摩擦系数降低的主要原因是相结构转变；还研究了载荷、摩擦环境对AlCrTiVMo-N氮化高熵合金薄膜摩擦学性能的影响规律，分析了其氮化高熵合金薄膜表面摩擦化学反应，明确了其摩擦学机理；并研究了不同热处理保温时间对AlCrTiVMo-N氮化高熵合金薄膜组织和性能的影响规律，确定了MoO3自润滑相对摩擦学性能提升作用。以上研究内容和研究成果，可为拓宽和加速高熵合金薄膜在高温摩擦磨损领域的应用提供基础数据和理论支撑。