Influence of Femtosecond Laser Surface Nanotexturing on the Friction Behavior of Silicon Sliding Against PTFE

Abstract

The aim of the present work was to investigate the influence of laser-induced periodic surface structures (LIPSS) produced by femtosecond laser on the friction behavior of silicon sliding on polytetrafluoroethylene (PTFE) in unlubricated conditions. Tribological tests were performed on polished and textured samples in air using a ball-on-flat nanotribometer, in order to evaluate the friction coefficient of polished and textured silicon samples, parallel and perpendicularly to the LIPSS orientation. In the polished specimens, the friction coefficient decreases with testing time at 5 mN, while it increases slightly at 25 mN. It also decreases with increasing applied load. For the textured specimens, the friction coefficient tends to decrease with testing time in both sliding directions studied. In the parallel sliding direction, the friction coefficient decreases with increasing load, attaining values similar to those measured for the polished specimen, while it is independent of the applied load in the perpendicular sliding direction, exhibiting values lower than in the two other cases. These results can be explained by variations in the main contributions to friction and in the wear mechanisms. The influence of the temperature increase at the interface and the consequent changes in the crystalline phases of PTFE are also considered.

Synergetic effects of surface texturing and solid lubricants to tailor friction and wear – A review

“…Most of these employed hard textured substrates such as stainless steel [179][180][181][182][183], bronze [184][185][186], silicon [187] or laminated ceramics [188,189], which were rubbing against an untextured PTFE nano-composite. Surface textures were mainly produced by LST using lasers with pulse durations ranging from micro- [179,181,[184][185][186] and nano- [188,189] to pico- [182] and femtoseconds [180,187]. Regarding the geometry of the textures, research effort has focused on dimples [179, 181-183, 185, 186, 188, 189], unidirectional grooves [180], grid-like textures, and circumferentially or radially aligned grooves [184].…”

Friction and Wear in Nanoscratching of Single Crystals: Effect of Adhesion and Plasticity

“…For instance, Chowdhury et al [ 9 ] studied the effect of normal load and sliding velocity on the tribological properties of aluminum using a pin-on-disc test; the results showed that the friction coefficient decreases when the normal load or the velocity increases, whereas the wear rate exhibits an opposite dependence on the normal load and sliding velocity. More experiments were performed to study the friction and wear under different conditions, including incidence angle [ 10 ], crystal orientation [ 11 , 12 ], coatings or oxidation [ 13 , 14 , 15 ], and surface texture [ 16 , 17 ]. In addition, the tribochemical reactions [ 18 ] at the sliding interface may also affect the material properties such as interfacial adhesion and material plasticity, resulting in the variation of frictional and wear processes.…”

Polystyrene Thin Films Nanostructuring by UV Femtosecond Laser Beam: From One Spot to Large Surface

“…Laser patterning can be a powerful technique for high-resolution surface nano-engineering [ 9 , 10 , 11 , 12 ]. It is a non-contact, mask-less, and flexible/versatile method with direct generation of micro- and nano-structures called laser-induced periodic surface structures (LIPSSs) observed on a wide range of materials, such as semiconductors [ 13 , 14 ], metals and alloys [ 15 , 16 , 17 , 18 , 19 ], metal oxides [ 20 , 21 , 22 , 23 ], inorganic compounds [ 24 , 25 ], and polymers [ 26 ]. Micro- and nano-structures could also be simultaneously observed in hierarchical patterns [ 19 , 24 ].…”