(Cr, V)2AlC 固溶体MAX相涂层的设计制备与高温润滑机制

The lubrication and wear performance at high temperature of moving key parts in the area of aerospace, national defense, nuclear power and other high-tech industries, closely affect the reliability and lifetime of the entire system. One of the effective ways to overcome this problem is to utilize high-temperature lubrication coatings. On the basis of the excellent high-temperature oxidation resistance and mechanical properties, the key idea of realizing the design of high-temperature lubrication coatings is the formation of the friction-induced lubrication phases which can provide good lubrication. Cr2AlC MAX phase coatings with close-packed hexagonal layer structure exhibit good oxidation resistance, but the shortcomings in mechanical and lubrication performances limit their application. With the help of solution strengthening effects and good lubrication of V2O5 Magnéli phase as well as our pre-work, we bring forward the study of V solid solution in Cr2AlC coatings. The amount of V is mainly controlled aiming to achieve (Cr, V)2AlC MAX phase coatings with a high purity. The effects of V content on the mechanical property, thermal stability and high-temperature tribological behavior will be established. The mechanism of solid solution strengthening will be discussed. The high-temperature diffusion of V element and oxidation behavior of the coatings will be clarified. The adaptive mechanism of (Cr, V)2AlC coatings will be revealed. These results will provide theoretical basis and technical support for the design and development of high performance MAX phase coatings.

航空航天、国防、核电等领域的关键运动部件在高温下的耐磨润滑问题，严重影响整个系统的运行稳定性和安全可靠性。施加高温润滑涂层是解决这一问题的有效途径。以优异高温抗氧化和力学性能为前提，通过摩擦诱导润滑相赋予其良好的润滑性能，是实现高温润滑涂层设计的核心思想。Cr2AlC MAX相涂层是一种具有密排六方结构的层状高温抗氧化涂层，但受限于其力学强度和润滑性能不足。借助固溶强化作用和Magnéli相V2O5良好的润滑特性，结合前期基础，本项目提出在Cr2AlC涂层中进行V固溶的设计思路，重点调控V元素的含量，实现高纯(Cr,V)2AlC MAX相涂层的可控制备，通过高温力学、热稳定性和高温摩擦行为的研究，探讨V的固溶强化机理，明晰润滑相V的高温扩散及涂层氧化规律，阐明高温抗磨减摩机制。研究结果将为设计和发展高性能MAX相涂层提供理论基础和技术支持。

施加高温润滑涂层是解决空天、国防、核电等领域关键运动部件磨损失效的有效途径。本项目以具有优异抗氧化性能的Cr2AlC涂层为基础，借助固溶强化作用和Magnéli相V2O5良好的润滑特性，提出在Cr2AlC M位固溶V实现强韧高温耐磨润滑一体化的涂层设计思路。首先，突破了(Cr1-x, Vx)2AlC MAX相涂层的高纯相低温可控制备，有效拓展了MAX相涂层在温度敏感基体上的应用，并利用原位XRD技术揭示了其成相机制；其次，阐明了Cr2AlC MAX相涂层在900-1100 ℃下的表界面元素扩散行为与氧化机理，建立了高温下涂层的微结构演变规律；最后，在此基础上，系统研究了(Cr1-x, Vx)2AlC MAX相涂层的宽温域摩擦学行为及耐磨润滑机制，提出了软质熔融态V2O5包裹(Cr, Al)2O3硬质颗粒的强韧自润滑复合氧化层是固溶体涂层高温抗磨润滑的关键，为设计新型高温自适应润滑涂层提供参考。在本项目资助下，在Corros. Sci.、Mater. Design、JMST、Tribol. Inter.等主流期刊上共发表SCI论文10篇，申请发明专利7项。