石墨烯改性多孔聚酰亚胺轴承保持架材料性能研究

Material Property Study on Graphene Infused Porous Polyimide Bearing Cage

多孔聚酰亚胺复合材料因具有良好的自润滑性而成为航天轴承保持架的主要选材。但该材料在使用过程中显现出导热性能差和易磨损等问题,缩短了轴承使用寿命,严重影响航天飞行器控制系统的可靠性。本工作通过机械混合添加石墨烯工艺制备得到了石墨烯改性多孔聚酰亚胺轴承保持架材料,并对复合材料的微观形貌与结构、导热性能和磨损性能等进行了表征与分析。结果表明,石墨烯改性多孔聚酰亚胺轴承保持架材料兼具良好的导热性能和耐磨性,当石墨烯含量为1.0%(质量分数)时,材料导热系数为0.41 W/(m·K),相比改性前提高36.9%;材料磨损率为43.25×10^(5)mm^(3)/(N·m),相比改性前提升27.3%。因此,改性后的复合材料保持架对延长航天轴承的使用寿命具有潜在的应用价值。

Porous polyimide composite has become the first choice of the material of aerospace bearing cages due to its good self-lubricating property.However,its poor thermal conductivity and wear resistance can lead to the shortened bearing service life and seriously affect the reliability of the control system of the aerospace vehicle.By mechanically mixing the graphene-modified porous polyimide composite,this work studied the microstructure,tribological properties and thermal conductivity of the material.The results show that the modified porous polyimide composite has excellent tribological properties and thermal conductivity.When the content of graphene is 1.0 wt%,the thermal conductivity and the wear rate of material is 0.41 W/(m·K)and 43.25×10^(5)mm^(3)/(N·m),respectively,increasing by 36.9%and 27.3%over those of the unmodified composite material.As such,the modified composite cage has potential applications for prolonging the service life of aerospace bearings.