Fri. May 24th, 2024

Ce of DLN films in ambient air has been attributed to interfacial sliding amongst the DLN film and graphitizedCoatings 2021, 11, 1203. https://doi.org/10.3390/coatingshttps://www.mdpi.com/journal/coatingsCoatings 2021, 11,two oftribofilm formed on the ball counterface [11,12], confirmed also by later tribological research of DLN films [157]. Of wonderful interest may be the friction and put on properties of DLN films beneath the circumstances altering the graphitized tribofilm formation, e.g., below liquid (water, oil) lubrication, at elevated temperatures, which would extend the functional capabilities of the coatings. Owing to low internal stresses [7], it truly is possible to create DLN films of comparatively big thickness (as much as 10 ), retaining the hardness and elastic properties [7,19,20], which enables a laser surface AICAR supplier texturing (LST) strategy to become applied for additional improvements of friction and wear properties of DLN coatings [16,20]. It was the smaller thickness (of 1 ) that strongly restricted the laser surface texturing of DLC films in early experiments of lubricated sliding, when the DLC film deposition onto laser-textured steel or AS-0141 custom synthesis silicon substrates had been proposed as an alternative texturing approach for DLC-coated surfaces [214]. This technique, alternative to direct laser surface texturing of DLC films, had disadvantages dealing with the require of mechanical polishing of laser-textured substrates prior to deposition of thin DLC films (to get rid of protruding rims around dimples) [21,23], and weaker adhesion of DLC coatings at the dimple edges leading towards the film delamination throughout sliding [22]. Not too long ago, femtosecond (fs) laser processing of DLN films has been demonstrated as an effective approach to handle the friction properties at the nano, micro, and macroscale [16,20,257] and to improve tribological properties of laser-textured DLN films in lubricated sliding [16,26]. Most of the critical findings for fs-laser-textured DLN films are connected to frequent patterns of parallel microgrooves and arrays of microcraters fabricated beneath specific irradiation circumstances limited to a offered structure size of 10 (groove width, crater diameter), structure depth of several microns and period of 20 . Further optimization of laser surface texturing of DLN films is necessary, aiming at fabrication of microstructures of decrease size and larger aspect ratio, and enhance in the throughput of microprocessing with high spatial precision. In this paper we focus around the effects of environments and laser surface texturing on tribological efficiency of DLN coatings. Firstly, we present the results of comparative tribological testing of DLN films in humid air and water beneath linear reciprocating sliding against steel and silicon-nitride balls, and demonstrate the friction pair-dependent put on character of the rubbing materials below water lubrication. Secondly, we present experimental information of high-precision surface texturing of DLN films with fs-laser pulses and fabrication of microcrater-based structures of hexagonal geometry, followed by tribological testing on the laser-textured DLN samples below oil lubrication at area temperature and 100 C. Additionally, we demonstrate how the nano-/microfriction behavior is changed inside the laser-structured region consisting of microcraters applying friction force microscopy in humid air. two. Supplies and Methods two.1. DLN Film Properties DLN films have been grown on silicon and steel substrates working with a plasma-assisted chemical vapor deposition (PAC.