Friction properties of micro/nanogroove patterns in lubricating conditions

Tribological properties can be improved by surface texturing; however, most of the conducted studies used microscale patterns. This study evaluated the lubrication properties of four different micro/nanogroove layouts (i.e., one straight layout and three different types of V-shaped layouts) created using the nanostripe fabrication technology. For each layout, microgrooves were arrayed at a pitch of 4 mu m or 6 mu m, and nanogrooves were formed on the ridge between these microgrooves. Friction tests were conducted at different loads and speeds using a single-crystal SiC disk as the counter specimen. We showed that patterns with 6 mu m pitch microgmoves had a lower friction coefficient than those with 4 mu m pitch microgmoves. The layouts with a higher ratio of nanogrooved area obtained a lower friction coefficient in high load and low speed conditions that are considered as boundary or mixed lubrication regimes.