Page 96 - 摩擦学学报2025年第8期

1194 摩擦学学报（中英文） 第 45 卷

3. Xi’an Aerospace Propulsion Institute, Shaanxi Xi’an 710100, China)
Abstract: To focus on the in-service performance of three types of solid lubricant coatings on the surface of aero-engine
fuel pump thrust bearings in aviation kerosene under simulated actual working conditions, to clarify the intrinsic
mechanism of frequent flake peeling during their use, and to select a coating with superior comprehensive performance.
This study also aims to provide guidance for the future development of protective coatings with better lubrication, wear
resistance, and anti-cavitation erosion functions. Using an MMW-1 vertical universal tribo-wear testing machine and an
ultrasonic vibration cavitation erosion testing machine, the tribological and cavitation erosion properties of three bonded
solid lubricating coatings mainly based on polyamide- imide (PAI) as a binder resin, MoS 2 /graphite-based bonded solid
lubricating coating, MoS 2 -based bonded solid lubricating coating, and graphite-based bonded solid lubricating coating,
in RP-3 aviation kerosene were comparatively studied. To simulate actual working conditions closely, the gear material
2Cr3WMoV was selected as the counterpart material for tribological tests. Based on optical microscopy (OM), three-
dimensional optical profilometry, and scanning electron microscopy (SEM), the original surface of the coatings and the
surface morphology after friction and cavitation erosion were analyzed. The phase composition of the coatings before
and after friction were compared using a high-resolution X-ray diffractometer (XRD). Raman spectroscopy was used to
characterize the components of the friction transfer films and the cavitation erosion peeling debris of the coatings, and
the protection and failure mechanisms of the coatings were discussed. The results showed that in the RP-3 medium, with
graphite as a lubricant, the friction coefficient of graphite-based bonded solid lubricating coating was as low as 0.083,
−6 3
and the wear rate was 1.5×10 mm /(N·m), exhibiting the best tribological performance. The original solid lubricant
particles embedded in the resin structure in the microstructure of MoS 2 /graphite-based bonded solid lubricating coating
and graphite-based bonded solid lubricating coating disappeared, and a layered structure similar to scales appeared.
There were no phase changes in the wear scar areas of the three coatings before and after friction, maintaining good
tribological chemical stability. During the friction transfer process, the intensity ratio of D peak to G peak of graphite
significantly increased, forming a graphite-like structure. The transfer films formed on the surface of the counterpart
material was beneficial for further reducing the friction coefficient. The three coatings were subjected to dual attacks
from cavitation load and cavitation heat in aviation kerosene, resulting in poor anti-cavitation erosion performance,
showing the characteristic of “filler particles falling off first accelerating flake peeling” of the coating, and a “melt
bead” structure not present in the original structure of the coating appears on the coating surface. Due to the poor load-
bearing capacity and large particle size of MoS 2 , the degree of cavitation erosion peeling was the most serious, resulting
the MoS 2 /graphite-based bonded solid lubricating coating to fall off with an area of up to 95.83% after 10 hours of
accelerated cavitation erosion. The anti- cavitation erosion performance of graphite-based bonded solid lubricating
coating was better, with a coating fall-off area of 84.73%. The Raman spectroscopy results of the fallen debris from the
three coatings indicated that cavitation erosion has little effect on the layered structure and phase composition of graphite
and MoS 2 . In summary, we believe that the comprehensive operational performance of graphite-based bonded solid
lubricating coating is more suitable for promoting the use of thrust bearing surfaces at this stage.
Key words: bonded solid lubricating coating; tribological properties; cavitation erosion performance; aviation kerosene;
failure mechanism

[7]
航空发动机燃油泵主要用于高压燃油的输送，其 产生磨损，改变了部件内部的接触状态与载荷分布 ，
中的止推轴承在齿轮高速旋转过程中主要承担轴向 导致部件几何尺寸和宏观性能均发生变化. 与此同
力，以保证燃油泵的稳定运行和航空发动机动力的稳 时，航空煤油在随止推轴承/齿轮摩擦副高速运动时，
定输出 [1-3] . 为了进一步提高发动机的功率和燃油的燃 其压强急剧变化，在低压区易于形成气泡群，而流经
烧效率，止推轴承/齿轮摩擦副的转速、载荷及燃油泵 高压区时随即发生溃灭，同时释放高速、高压的微射
中油料介质的温度都不断增加，导致使用铜合金制备 流和冲击波并产生瞬间高温 [8-10] ，导致部件壁面在高
的止推轴承所遭受的磨损以及气蚀损坏更加严重. 首 频冲击和高温灼伤下发生疲劳剥落，从而形成孔洞，
先，在高速和高载条件下，低黏度航空煤油很难在摩 对材料造成气蚀损伤 [10-12] . 也就是说，止推轴承表面同
擦副界面上形成连续的油膜，容易引发固/固界面直接 时存在磨损和气蚀2种形式的损伤，且二者之间还会
接触 [4-6] ，造成摩擦界面尤其是硬度相对较低的止推轴 产生耦合加剧的破坏作用. 特别值得关注的是，2种单
承表面物质产生塑性变形、不断被去除甚至断裂，即 一损伤造成的材料失效尚未很好地解决，二者损伤效