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. 2021, 11,two oftribofilm formed on the ball counterface [11,12], confirmed also by later Imeglimin MedChemExpress tribological studies of DLN films [157]. Of great interest is definitely the friction and wear properties of DLN films under the circumstances changing the graphitized tribofilm formation, e.g., below liquid (water, oil) lubrication, at elevated temperatures, which would extend the functional capabilities on the coatings. Owing to low internal stresses [7], it truly is doable to make DLN films of relatively massive thickness (as much as ten ), retaining the hardness and elastic properties [7,19,20], which makes it possible for a laser surface texturing (LST) strategy to be applied for additional improvements of friction and wear properties of DLN coatings [16,20]. It was the tiny 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 silicon substrates had been proposed as an option 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 remove protruding rims about dimples) [21,23], and weaker adhesion of DLC coatings at the dimple edges top for the film delamination through sliding [22]. Recently, femtosecond (fs) laser processing of DLN films has been demonstrated as an effective method to control the friction properties in the nano, micro, and macroscale [16,20,257] and to enhance tribological properties of laser-textured DLN films in lubricated sliding [16,26]. Many of the crucial findings for fs-laser-textured DLN films are related to normal patterns of parallel microgrooves and arrays of microcraters fabricated below certain irradiation conditions limited to a provided 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 2-Bromo-6-nitrophenol custom synthesis reduce size and larger aspect ratio, and enhance in the throughput of microprocessing with higher spatial precision. In this paper we focus on 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 under linear reciprocating sliding against steel and silicon-nitride balls, and demonstrate the friction pair-dependent wear character on the rubbing supplies beneath water lubrication. Secondly, we present experimental data 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 with the laser-textured DLN samples beneath oil lubrication at space temperature and one hundred C. In addition, we demonstrate how the nano-/microfriction behavior is changed within the laser-structured location consisting of microcraters employing friction force microscopy in humid air. two. Materials and Methods two.1. DLN Film Properties DLN films have been grown on silicon and steel substrates making use of a plasma-assisted chemical vapor deposition (PAC.