Self-repairing mechanism and surface characterization of compressor vanes lubricated with oil added with magnesium silicate hydroxide nanorods

Using magnesium silicate hydroxide as additive of lubricating oils for reducing friction in engineering equipment/machinery has been researched intensively. However, some mechanism relating to the growth of the self-repairing layers on the won surfaces is still not clearly explained. At the same time, using magnesium silicate hydroxide (MSH) in the form of nanorods showed great promise in reducing friction and wear. In this study, surface-modified MSH in the form of nanorods was used as additive of polyolester oil (POE) which was then used for the lubrication of compressor vanes. The sample parts were studied on the morphology and the microstructure of the self-repairing layer in a great depth. The results showed that self-repairing layers with different thicknesses were generated on the worn surfaces when the POE with 1 wt.% nanorods-MSH was used. It was found that the self-repairing layers consist of organic–inorganic composite membranes, and with increase of working time of the compressor vanes, the self-repairing layers become denser and thicker, while their micro-structural form remains to be similar. The situ-repairing capability of the metal surfaces (roller-vane pair of the compressor) enforced by the MSH nanorods is very significant, indicating high potential for industrial applications where boundary and mixed lubrications are needed.