During both the initiation and cessation phases of machine operations, as well as during load variations, the friction pair often experiences substantial wear due to insufficient lubrication. This thesis addresses the friction and wear challenges encountered in various lubrication states, including dry friction under starved lubrication conditions. A "pocket-texture" surface was designed and optimized to improve tribological performance under starved lubrication. The principal findings are as follows:

To overcome the issue that lubrication stored in conventional textured holes is not easily replenished, the concept of a "pocket-texture" surface, combining oil storage pocket and textures, was proposed. The parameters of the new texture were theoretically optimized from the perspectives of fluid-film bearing and anti-starvation. Based on JFO boundary processing cavitation issues, a rough surface starved lubrication theoretical model was established, considering elastic deformation factors. The effects of texture parameters (diameter and depth) on film thickness, pressure, and elastic deformation were studied for different oil supply conditions. The selection of texture parameters under operating conditions (load, speed, and lubricant viscosity) was determined, and the mechanism of textured surface under starved lubrication was studied. From the perspectives of surface deformation, oil extrusion, and reabsorption angle, the contact position, the texture plate's thickness, and the texture's diameter were optimized. A finite element analysis model of pocket-texture surface was established. The edge deformation promotes the flow of lubricant in the lubricant pocket and the contact area when the contact area is close to the edge of the texture holes. The thickness of the texture plate has a significant effect on deformation, while the diameter has an insignificant impact.

Pocket-texture surface was prepared, and its tribological properties were experimentally tested. The tribological behavior showed a strong dependence on the amount of surface deformation. For the design parameter of textured plate thickness, combined with the results of the simulation, it is found that the reasonable range of deformation amount is 0.37 ~ 0.44 μm. For the design parameter of texture diameter, the deformation ranges of the pocket-texture surfaces are close, and the friction behavior under different operating conditions showed that the texture diameter mainly affects the dynamic pressure effect. Using a high-speed camera, the designed textured surface was experimentally observed. Through periodic deformation, the lubricant in the oil pocket is squeezed out at the front of the contact area and sucked at the rear end. The tribological performance with pocket texture is successfully improved. A pocket-texture surface with better design parameters was selected to test its friction performance and simulate its deformation under low speed and heavy load. It effectively improved the tribological behavior under starved lubrication.

Utilizing the viscosity and polarity matching of lubricant, the lubrication state can transition from starved lubrication to mixed lubrication. The tribological behavior of pocket-texture surfaces under starved lubrication has been improved by lubricants of varying characteristics, namely low-viscosity non-polar white oil, high-viscosity non-polar silicone oil, and high-viscosity polar castor oil. The texture structures can decrease the contact surface energy, encouraging the formation of boundary lubricant film. Among the three oils, castor oil had the lowest friction and wear coefficients, while white oil was the highest. Lubricants of higher viscosity can produce a thicker oil film to separate friction surfaces (especially in textured surfaces), thereby promoting the formation of mixed lubrication.

Two typical nanoparticles, fluorinated graphite, and multi-walled carbon nanotubes, were selected to study the tribological behavior of the pocket-texture surface under different working conditions and explore the synergy effect between nanoparticles and pocket-texture surfaces. The friction coefficient of 0.5 wt.% ~ 1 wt.% fluorinated graphite nano-oil was lower than that of white oil. The friction coefficient of 0.05 wt.% carbon nanotube nano-oil was lower than that of white oil, while the friction coefficient of 0.075 wt.% and 0.1 wt.% carbon nanotube nano-oil was higher than that of white oil. However, the wear amounts of all nano-oils were minorer than those of white oil. Nanoparticles enter the contact area with lubricant, filling the surface asperities and reducing the contact probability of the surface asperities, thereby improving the tribological behaviors. However, when the concentration is too high, the nanoparticles are prone to aggregation, increasing the friction coefficient.

This thesis mainly aims to solve starved lubrication, design and process a pocket-texture surface, and determine the design parameters. Using the synergy of lubricant with nanoparticles, the tribological behaviors of surfaces under starved lubrication are improved. The results provide preliminary theoretical and experimental support for longevity design under starved lubrication.