Low Friction and High Solid-Solid Contact Ratio—A Contradiction for Laser-Patterned Surfaces?
AbstractRecording of Stribeck-like curves is a common way to study the effect of laser-patterned surfaces on the frictional efficiency. However, solely relying on the coefficient of friction when identifying the lubrication regime and the underlying working principles can be misleading. Consequently, a ball-on-disc tribometer was combined with an electrical resistivity circuit to simultaneously measure Stribeck-like curves and solid-solid contact ratios for polished and laser-patterned samples. Line-like surface patterns with different periodicities were produced by direct laser interference patterning on steel substrates (AISI304). The reference shows a Stribeck-like behavior well correlating with the contact ratios. The behavior deviates for high sliding velocities (high contact ratios) due to a loss of lubricant induced by centrifugal forces pulling the lubricant out of the contact zone. In contrast, the solid–solid contact ratio of the laser-patterned samples is around 80% for all sliding velocities. Those values can be explained by higher contact pressures and the structural depth induced by the surface topography which make a full separation of the surfaces unlikely. Despite those high values for the contact ratio, laser-patterning significantly reduces friction, which can be traced back to a reduced real contact area and the ability to store oil in the contact zone. View Full-Text
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Bettscheider, S.; Grützmacher, P.G.; Rosenkranz, A. Low Friction and High Solid-Solid Contact Ratio—A Contradiction for Laser-Patterned Surfaces? Lubricants 2017, 5, 35.
Bettscheider S, Grützmacher PG, Rosenkranz A. Low Friction and High Solid-Solid Contact Ratio—A Contradiction for Laser-Patterned Surfaces? Lubricants. 2017; 5(3):35.Chicago/Turabian Style
Bettscheider, Simon; Grützmacher, Philipp G.; Rosenkranz, Andreas. 2017. "Low Friction and High Solid-Solid Contact Ratio—A Contradiction for Laser-Patterned Surfaces?" Lubricants 5, no. 3: 35.
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