| ABSTRACT:Lubrication condition can be improved by using lubricating oil with ore self-repairing powder which is composed of Hydroxyl magnesium silicate and the friction and wear reduced. Researchers also found the phenomenon of self-repair in situ worn areas online to make up wear. But the working condition adaptability and mechanism of this self-repairing additive need to further research. The investigation in two aspects was carried out in this thesis.First, on the analysis of two diesel locomotive cylinders lubricated with self-repairing additive which travelled for 600000 km, we found restoration film on the surface. Microscopic surface were observed by using three-dimensional morphology instrument and scanning electron microscopy. The chemical composition of the film was analyzed by EDAX and XPS and the hardness was measured by a hardmeter. The results show that the self-repair film mainly is composed of C,O and Fe, its surface had a higher C content, the hardness is 2 times the substrate hardness.Secondly, the UMT was used to investigate the influence of additive on the friction coefficient, friction material,the original surface roughness and load. Following conclusions can be given through the observation and analysis of wear scar morphology, elemental composition and micro-hardness:wear reduced because of the powder additive, the effect of antifriction had become even more obvious with the increase of the load. The preliminary exploration was performed on the effect of temperature on the additives by SRV tester, and it was found that the influence of temperature on the friction coefficient was not significant.It can be inferred that hydroxyl silicate additive is not directly involved in the film formation but plays a catalytic role.This thesis provides a reference on discussion on self-repairing mechanism and promotion of self-repairing technology from the theoretical and practical aspects on the basis of the analysis and design on the industrial application and laboratory tests.
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