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目的 为石墨增强聚酰亚胺复合材料在海水环境下的摩擦学应用提供实验依据.方法 利用SST-ST销/盘摩擦试验机,研究了质量分数为15%石墨增强聚酰亚胺复合材料与17-4PH不锈钢组成的摩擦副在海水介质中的摩擦学性能,并与干摩擦和纯水润滑条件下的摩擦学性能进行比较.结果 聚酰亚胺复合材料在干摩擦下的摩擦系数和磨损体积最大,分别为0.134、1.930 mm3.干摩擦条件下,聚酰亚胺复合材料的磨损表面存在较深的犁沟,在犁沟周围出现了材料塑性流动及粘着剥落现象,对偶件表面有聚酰亚胺复合材料转移.磨损机理主要表现为磨粒磨损、材料塑性变形以及粘着和剥落.在纯水润滑下,聚酰亚胺复合材料表面存在较多材料粘着撕裂现象,同时存在宽浅不一的犁沟,磨损机理主要为粘着磨损和磨粒磨损.在海水润滑下,复合材料的摩擦系数和磨损体积最小,分别为0.086、1.235 mm3,材料磨损表面十分光滑,只有沿运动方向存在少量轻微犁沟,磨损机理主要表现为磨粒磨损.结论 石墨增强聚酰亚胺复合材料在海水中的摩擦学性能优于干摩擦和纯水环境下的摩擦学性能.

The work aims to provide an experimental basis for tribological application of polyimide composites in seawater. Tribological properties of friction pair consisting of 15% graphite-reinforced polyimide composite and 17-4PH stainless steel in seawater were studied using SST-ST pin-on-disk friction tester, the tribological properties under dry friction and pure water lu-brication were compared. The polyimide composites had the highest friction coefficient and wear volume (0.134 and 1.930 mm3, respectively) under dry friction. Material plastic flow and adhesive peeling were present around deep furrows on the worn sur-face of PI composites under dry friction, polyimide composites transferred on the surface of mating plate. The wear mechanism was mainly abrasive wear, plastic deformation, adhesion and peeling under dry friction condition. Provided with pure water lu-brication, the surface was subject to common material adhesion and tearing, shallow and wide furrows on the worn surface of PI composites. The wear mechanism was mainly adhesive and abrasive wear. Provided with seawater lubrication, friction coeffi-cient and wear volume were the minimum (0.086 and 1.235 mm3, respectively). The worn surface was very smooth and only a few slight furrows were present in direction of motion, the wear mechanism was mainly abrasive wear. Graphite reinforced po-lyimide composites have better tribological properties in seawater than those under dry friction and pure water lubrication.