Influence mechanism of surface treatment on the wear and adhesion at the frictional interface of 2A14T6 aluminum alloy

Current research on satellite and rocket separation structures mainly focuses on structural design and finite element stress analysis. The strap locking device, which has the advantages of high separation reliability and low impact on satellite, is widely used in the space field. However, adhesive wear occurs very easily on the satellite and rocket separation surface of the belt locking device. Therefore, it is necessary to investigate the effect of adhesive wear on the separation surface of the satellite and rocket at different surface states. In this study, friction pair of the 2A14T6 aluminum alloy was prepared by surface treatment through chromium plating or epoxy resin coating. Tangential fretting wear experiments were conducted on the treated surfaces in the flat-on-flat contact mode in an SRV-IV multifunctional tester to investigate the evolution law of friction, adhesion, and fretting damage at varying positive pressures. The results revealed that the friction coefficient of the samples with chromium plating and epoxy resin coating decreased gradually and exhibited relatively small fluctuations with increasing positive pressure compared with those of the samples without surface treatment. For the samples with epoxy polymer coating, the fretting running state remained in the gross slip regime (GSR), and the frictional dissipation energy and wear debris gradually increased with increasing positive pressure. However, the fretting running state gradually changed from the GSR to mixed fretting regime for the samples with chromium plating or without surface treatment. Meanwhile, spalling, oxidation, and adhesion of wear debris occurred in the fretting damage zone. Specifically, oxidation and interface adhesion were more severe for the samples without surface treatment. The main mechanism of fretting wear at the interface involved oxidation wear, abrasive wear, and adhesive wear. The epoxy-based polymer lubrication coating prepared in this study can effectively attenuate the adhesive wear of the 2A14T6 friction pair of separation surfaces.