کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
701822 | 1460798 | 2013 | 7 صفحه PDF | دانلود رایگان |
In this work, the influence of surface topography and micro structural changes on the tribological properties of tetrahedral amorphous carbon coatings (ta-C) structured using a holographic technique the direct laser interference pattering (DLIP) is investigated. By utilizing a nanosecond pulsed UV-laser (wavelength 355 nm), both ablation and graphitization thresholds were determined as a function of the pulse number. Incubation effects for the ablation threshold ( ~ 205 mJ cm− 2) were found to be negligible. However, for the graphitization of the film thresholds varying from 47 to 74 mJ cm− 2 were observed depending on the number of laser pulses utilized (from 1 to 30) and thus obtaining an incubation factor of 1.13. Using two- and three-beam interference setups, dot- and line-like periodic arrays were fabricated. The tribological performance of these patterns was investigated under reciprocating sliding with a ball on disk method under non-lubricated conditions showing that coefficient of friction can be reduced from ~ 0.089 (un-patterned) to ~ 0.055 patterned ta-C ( ~ 30% reduction). The results can be explained based on the reduction of surface contact area combined with high hardness as well as the good intrinsic tribological properties of the ta-C films.
Figure optionsDownload as PowerPoint slideHighlights
► DLIP of micrometer thick ta-C to fabricate periodic arrays with μm resolution
► Depending on the laser fluence, graphitization and ablation were observed.
► Dot- and line-like patterns were fabricated.
► Surface patterning results in 30% reduced friction of ta-C.
Journal: Diamond and Related Materials - Volume 33, March 2013, Pages 20–26