航空齿轮复合涂层结构剥离失效微观机理研究

In order to ensure the safe and reliable operation of the aircrafts and avoid crash accidents, the current aviation industries require gears manufactured with more enhanced flanks to resist the fatigue failure for the transmission of motion and power. Surface composites involving coating layers and hardened layers can effectively improve the damage resistance of gear flanks. However, the improper contact of gear teeth may lead to delamination of such layers and even cause transmission failures. The proposed project carries out the concerned study based on the analysis of the gear features and kinetic characteristics. A gear contact model is developed with the interaction among composite layers fabricated by TiN layers and nitrided layers and crack defects accounted for at starvation conditions. The solution integrates the material/solid/fracture/interfacial mechanics, and the algorithms of the fast Fourier transform and conjugate gradient method are employed. The model is validated in different aspects upon the finite element method, the indentation test and friction test of multi-layered samples and the performance test of layered gears. This research aims to study the response of surface layers and the property enhancements of the surface modification and reveal the micro delamination mechanisms of layers and gear failure due to fatigue accumulation. The study may potentially improve gear transmission performance and provide guidance for fatigue resistance design.

为保证航空飞行器的安全可靠运行，避免由于传动故障导致飞行事故，现代航空工业对齿轮表面抗疲劳性能的要求日益苛刻。涂层/硬质层复合涂层结构是提升齿轮表面破坏抵抗力有效手段，然而不良接触作用下涂层结构易疲劳剥落造成传动失效。本项目基于齿轮的结构特征与动力学规律，系统地关联材料/固体/断裂/界面等力学理论，应用快速傅里叶变换、共轭梯度法等数值算法，建立乏油润滑服役环境下表面改性氮化钛涂层/渗氮硬质层复合涂层与裂纹缺陷耦合干涉作用的齿轮啮合接触模型，基于有限元仿真软件、复合涂层样件的压痕实验与摩擦性能实验、涂层齿轮综合性能实验等，多角度、多层次验证模型的有效性并对模型修正，分析研究复合涂层材料的润滑接触响应，揭示涂层材料梯度结构属性的组织性能强化规律，探索啮合承载作用下涂层剥离微观行为机制和疲劳损伤累积失效演化机理，为航空齿轮传动抗疲劳性能提升提供一套可行的设计理论与方法。

现代航空工业表面强化技术可有效提升齿轮表面破坏抵抗力，提升界面摩擦性能，然而，涂层/硬质层组成的复杂材料结构受载时各层界面处产生应力集中，易萌生裂纹造成材料表面损伤引发系统失效。本项目建立了乏油润滑服役环境下表面改性硬质复合涂层与裂纹缺陷耦合干涉作用的齿轮啮合接触模型，整合实验测试手段验证模型的准确性和有效性，分析研究复合涂层材料的润滑接触响应，揭示涂层材料梯度结构属性的组织性能强化规律，探索啮合承载作用下涂层剥离微观行为机制和疲劳损伤累积失效演化机理，为航空齿轮传动抗疲劳性能提升提供一套可行的设计理论与方法。