Tribological studies of low and high viscous oils lubricated heavily loaded textured point contacts under the reciprocating motion

Abstract

The tribo-performance behaviors of lubricated textured point contacts have been explored herein at relatively high contact loads (up to 3 GPa) under reciprocating motion (0.2 and 0.4 m/s) employing low (ν@40 ℃ = 100 cSt) and high (ν@40 ℃ = 422 cSt) viscous oils. In this experimental study, two contacts (flat conventional surface vs. polished ball and textured flat surface vs. polished ball surface) have been created for the investigations of friction, wear, and contact potential (ability for film formation). It is found that in the presence of texture at the concentrated contacts, the coefficient of friction and wear have reduced considerably with high viscous oil irrespective of operating parameters. However, low viscous oil has yielded an increase in the wear under identical operating parameters. The contact potential (an indirect indication of film formation during the running-in period) in the presence of texture develops rapidly as compared to the conventional surface with both oils. It has demonstrated a reduction in the running-in period in the presence of textures at the contacts. The optical microscope images of worn surfaces of balls and tracks have also been presented for the quantification of wear and understanding of the associated mechanisms.