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Tests were carried out using a pin-on-disc tester under starved lubrication conditions. To achieve a conformal contact, a special construction was used with an adjustable counter sample. Textured surfaces with two dimple patterns (spiral an radial) and four shapes (circle, oval, triangle, and chevron) were tested. The contact area was lubricated with L-AN-46 oil. Before the tests, surface topographies of the discs were measured by a white light interferometer Talysurf CCI Lite. Tests showed that, in starved lubrication conditions, oil pocket shape and pattern affected the friction force.

The experiments were carried out using a block-on-ring tester. The block samples made from bronze CuSn10P of 138 HB hardness were burnished to obtain surfaces with circular oil pockets. Rings were made from 42CrMo4 steel of hardness 40 HRC. Friction tests were conducted at a constant normal load of 900 N. Tests were carried out at increasing sliding speeds of the range 0.08 – 0.82 m/s, starting from the lowest speed. The every speed was maintained for two minutes. The tested assembly was inserted in the reservoir of mineral oil L-AN 46. It was found that the dimple presence on block surface reduced the friction coefficient substantially compared to non-textured turned surfaces. The area density of dimples smaller than 15% (particularly 4.5% and 6%) was beneficial.

Experiments were carried out using pin-on-disc tester in conformal lubricated contact conditions for different normal loads. Surface texturing was done using abrasive jet machining with the application of laser cut mask. In order to eliminate the effect of different input variables in all the experiments, pit-area ratio and sizes of oil pockets were very similar. Five types of oil pocket arrays were tested: radial, concentric, spiral, of a square arrangement, and of a random arrangement for 5% and 17% of pit-area ratio. Different dimple diameters caused various oil pocket densities. The experiments were also made for untextured polished discs. During tests, the friction force was monitored as a function of time. Before and after tests, disc surface topography was measured using a white light interferometer Talysurf CCI Lite. The beneficial effect of surface texturing was obtained for spiral arrays of dimples on disc surface. The presence of a radial array of oil pockets resulted in the worst tribological properties of tribological assemblies containing textured discs.

Various machining methods are currently used to obtain the best co-action of sliding surfaces. Application of two-process surfaces led to a decrease of frictional resistance. Textured surfaces after abrasive jest machining are practical examples of two-process topographies. The results of the application of textured discs with the same array of oil pockets of similar sizes, but with different roughness in areas free of dimples, are presented in this paper. It was determined that after this type of machining, the effect of the friction force decrease was caused by surface texturing.