The clarification of low friction mechanism in oil lubrication for B-DLC coating by in-situ observation of friction area
At a Glance
Section titled āAt a Glanceā| Metadata | Details |
|---|---|
| Publication Date | 2018-01-01 |
| Journal | Kiso Junkatsu Sekkei Bumon Kouenkai kouen rombunshuu/Kiso Junkatsu Sekkei Bumon Koenkai koen ronbunshu |
| Authors | Tatsuya Okamoto, Hidenori Nishimura, Noritsugu Umehara, Motoyuki Murashima, Takayuki TOKOROYAMA |
| Institutions | Railway Technical Research Institute, Nagoya University |
| Citations | 1 |
Abstract
Section titled āAbstractāIn order to increase energy efļ¬ciency, it is important to reduce friction loss in mechanical sliding parts. Diamond-Like Carbon (DLC) coatings have been widely accepted as materials for reducing friction. Its physical properties and frictional characteristics change depending on the bonding states of the carbon atom and the contained elements. Boron-doped DLC (B-DLC) coating was showed low friction coefficient (Ī¼<0.01) in FAQ oil. To clarify the low friction mechanism of B-DLC coating in PAO oil lubrication, we measured reļ¬ectance spectrum at friction area in-situ by reflectance spectroscopy. We obtained the surface roughness of B-DLC coating, thicknesses and polarizability of the transformed layer formed on bulk B-DLC coating during friction test by analyzing reļ¬ectance spectrum. We suggest that the increment of the polarizability of the transformed layer has an effect on increment of Van der Waals force between transformed layer and PAO oil. By increasing Van der Waals force, oil molecular adsorb on the transformed layer, and then the friction coefļ¬cient of boundary lubricant area of B-DLC coating decrease.