Tribological Properties of Bronze with Different Surface Wettability

Micro-dimple arrays with various diameter and area coverage on bronze substrate were fabricated by through-mask Electrochemical Machining using ultrashort pulses and the textured surface was treated with fluorinated chlorosilanes. The surface wettability of lubricating oil was characterized by a contact angle meter. Friction tests were performed using a ball-on-disk apparatus and worn surface morphologies were observed through scanning electron microscopy. The investigation showed that the oleophobicity of F1060-treated textured bronze surfaces increased with the increasing micro-texturing density. Compared with the oleophilic smooth and textured surface,oleophobic smooth and textured surfaces exhibited lower friction coefficient with a reduction of 21.2%,33.6%,respectively and lower wear rate with a decline of 17.3%,4.9%,respectively. Under the condition of ball-on-disk experiment with 3 N load using the surface textured samples with 4 kinds of different diameter of micro-dimples,oleophobic surface with area ratio of 4.9% and 8.7% had an optimal friction reduction effect when a diameter was smaller or larger than 30 μm respectively.