The Effect of Oil Pockets Shape and Distribution on Seizure Resistance in Lubricated Sliding

Abstract

The results of experimental investigations on the effect of the oil pockets existence on seizure resistance of sliding elements are presented. Seizure tests were conducted with block-on-ring apparatus at increasing pressure. The stationary block (counter specimen) contacted the rotating steel ring (specimen). The tested assemblies were lubricated by oil L-AN 46, which was heated to 30°C before each experiment. The sliding was unidirectional. The block was a part of a bearing sleeve-hardened EN-GJS 400-15 cast iron with a hardness value of 50 HRC. The ring samples, 35 mm in diameter, were made from hardened 42CrMo4 steel of hardness 32 HRC. The friction force and temperature near the contact zone were measured during the tests. Some variants of specimen surfaces were created by burnishing technique. They were characterised by the oil pocket density, the holes depth, length, and width. The oil pockets existence of area density of 10% on the ring surface improved seizure resistance of the sliding pair steel-cast iron for speed of 0.27 m/s. The pit shape and orientation are very important, too.

Friction Reduction in Unidirectional Lubricated Sliding Due to Disc Surface Texturing

“…The bottoms with the converging shapes helped to minimize friction by generating hydrodynamic lift. Galda et al [30] obtained the same finding after testing dimples of the long drop shape with the sloped bottoms.…”

“…They found that chevron pattern pointing along the direction of motion could lead to film thickness growth. Wang [29] and Galda et al [30] observed that orientation of triangle-shaped oil pockets and dimples of long drop shape, respectively, had a substantial effect on tribological behaviors of sliding pairs. The lowest friction force was achieved when one side border orthogonal to the sliding direction first entered the contact zone.…”

Reverse Problem in Surface Texture Analysis—One-Process Profile Modeling on the Basis of Measured Two-Process Profile after Machining or Wear

“…They are called textured surfaces. Surface texturing is an option of surface engineering resulting in significant reductions of the frictional resistance in mixed and fluid lubrications, wear, and the inclination to seizure by creating oil pockets (dimples or cavities) on the sliding surfaces [5][6][7][8][9][10].…”

The effect of vibratory and rotational shot peening and wear on fatigue life of steel

“…The presence of oil-accumulating cavities on the interacting surfaces has a positive effect on lubrication but, on the other hand, leads to an increase in unit pressure. It was found that seizure resistance depends on the distribution of lubricant-accumulating cavities and their shape [3]. In shot peening, the impact of shot impacting a surface leads to formation of microcavities which can serve as "lubricant reservoirs."…”