THE EFFECTS OF DIMPLE SIZE AND DEPTH ON FRICTION REDUCTION UNDER BOUNDARY LUBRICATION PRESSURE

摘要

The effect of dimple size on sliding friction conducted under boundary lubrication conditions using a four-ball wear tester was investigated. The contact geometry used was a ballon-three-flats arrangement using 52100 steel balls and flats. Circular dimples of various diameters (20-60 μm) and depth (2.5-10 μm) were fabricated using micro-lithography followed by electrochemical etching. Tests were conducted from 98-296N loads and 0.2-1.3 m/s speeds. Results suggest that smaller dimples with shallower depth achieve higher level of friction reduction under these test conditions.