Effect of vein-bionic surface textures on the tribological behavior of cylindrical roller thrust bearing under starved lubrication

To reveal the effect of vein-bionic surface textures on the tribological behavior of cylindrical roller thrust bearings (CRTBs) under starved lubrication, six kinds of leaves (Forsythia, Clausena lansiu, Ash, Purple leaf plum, Pipal and Apricot) were chose and their simplified patterns were fabricated on the shaft washers of CRTBs using laser surface texturing. The coefficients of friction (COFs) of vein-bionic textured bearings were measured using a vertical universal wear test rig. Their mass losses and worn surfaces were also characterized. The results show that: There is important influence of the symmetry of vein-bionic textures and the number of secondary veins on the friction and wear properties of vein-bionic textured CRTBs under starved lubrication. Compared to the smooth group, the COFs and mass losses of vein-bionic textured bearings are all reduced. Among all groups, the tribological performance of bearings with a pattern inspired from Ash is the best. Its wear loss is reduced by 16.23% and its COF is reduced by 15.79%. This work would provide a valuable reference for the raceway design and optimization of roller rolling element bearings.

DEVELOPMENT OF ELEMENTS OF THE TECHNOLOGY OF CREATION OF THE BIONIC STRUCTURE OF PROTECTIVE CLOTHING MATERIAL AGAINST THE THERMAL EFFECTS OF UNDERWATER WELDING

The article is devoted to research and development of technology elements for designing and manufacturing a new polymer material based on heat-resistant silicone with a special surface structure in the form of an ordered relief matrix that simulates a bionic surface (“shark skin”), created on the basis of digital processing of bionic models, providing a barrier against thermally dangerous particles of underwater welding. In order to determine the stability of the developed material to the thermal effects of a short-term open flame, experimental tests were carried out, which made it possible to determine that the damage to the surface of the new silicone material is insignificant. It does not lead to the destruction of the overall thickness of the protective material and further risks for the internal foam heat-protective layer of wetsuits – damage to the surface of the protrusions of the relief matrix (no more than 40 % of the initial parameters). The developed material allows one to increase the protection of the main surface of the clothing material.