钴基合金刷丝与碳化铬涂层高线速度磨损行为研究
收藏资源简介：
在超高速磨损试验器上开展刷式密封磨损试验，摩擦副为GH5605钴基高温合金刷丝束和喷涂碳化铬耐磨涂层的跑道试样，最高摩擦线速度达到400 m/s. 利用扫描电镜和能谱分析研究了摩擦表面的磨损形貌及材料成分，发现试验后的碳化铬涂层存在材料剥落和刷丝材料附着，刷丝尖端出现以犁沟和涂抹为主要特征的磨损，且摩擦线速度达到400 m/s时出现刷丝尖端粘连和严重氧化现象. 通过分析刷丝尖端磨损形貌的形成机制及摩擦表面的材料转移机理，认为刷丝尖端的主要磨损机制为二体磨粒磨损，而涂层的材料剥落现象会加剧其对刷丝的磨粒磨损作用. 使用共聚焦显微镜测量了磨痕深度，并与转子离心涨大变形量进行对比分析，分析结果表明超高线速度条件下转子的离心涨大增加了刷丝束和跑道涂层间的干涉，显著加剧了摩擦副的磨损.
Brushed seal wear tests were conducted on an ultra-high speed wear tester, utilizing a friction pair consisting of GH5605 cobalt-based superalloy brush filament bundles and runner specimens with thermally sprayed chromium carbide wear-resistant coatings. The maximum linear friction velocity reached 400 m/s. Scanning electron microscope (SEM) and energy-dispersive X-ray spectroscopy (EDS) were employed to investigate the wear morphology and material composition of the friction surfaces. It was observed that post-test chromium carbide coatings exhibited material spalling and adhesion of brush filament materials; the brush filament tips displayed wear primarily characterized by plowing grooves and smearing, and when the linear friction velocity reached 400 m/s, sticking and severe oxidation occurred at the filament tips. By analyzing the formation mechanism of the wear morphology at the brush filament tips and the material transfer mechanism on the friction surfaces, it is determined that the dominant wear mechanism of the brush filament tips is two-body abrasive wear, and the material spalling of the coating exacerbates the abrasive wear inflicted on the brush filaments. The wear scar depth was measured using a confocal microscope, and a comparative analysis was conducted with the centrifugal expansion deformation of the rotor. The analysis results demonstrate that under ultra-high linear velocity conditions, the centrifugal expansion of the rotor increases the interference between the brush filament bundle and the runner coating, significantly aggravating the wear of the friction pair.
