Functionality Investigations of Dry-Lubricated Molybdenum Trioxide Cylindrical Roller Thrust Bearings

verfasst von

Dennis Konopka, Florian Pape, Norman Heimes, Bernd-Arno Behrens, Kai Möhwald, Gerhard Poll

Abstract

In addition to using conventional lubricants, such as oil and grease, rolling bearings can also be used with a dry lubricant. For example, the use of dry lubricant systems is necessary when the application of oils or greases is not possible (e.g., at high temperatures or in aerospace applications). The requirements of a solid lubricant are to reduce friction and wear of mechanical contact partners. In this work, a molybdenum-based coating system was applied by means of physical vapor deposition (PVD). The coating system consists of a molybdenum (Mo) reservoir with molybdenum trioxide (MoO

₃) as the top layer. The MoO

₃, which is particularly important for the run-in and the lubricating effect, is intended to continuously regenerate from the reservoir via tribo-oxidation. To determine the friction and wear behavior, cylindrical roller thrust bearings were used. Experiments demonstrated that the lubrication system is effective and that the frictional behavior has been improved. On the one hand, the frictional torque of the rolling bearings has been considerably reduced and, on the other, significantly extended operating times have been determined compared to unlubricated reference experiments. Simultaneously, material analyses have been carried out by means of scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX). The investigations showed that the MoO

₃ was transferred to uncoated bearing components. This improved the tribological behavior and reduced abrasive and adhesive wear.

Organisationseinheit(en)

Institut für Maschinenkonstruktion und Tribologie
Institut für Umformtechnik und Umformmaschinen
Institut für Werkstoffkunde

Typ

Artikel

Journal

COATINGS

Band

12

ISSN

2079-6412

Publikationsdatum

26.04.2022

Publikationsstatus

Veröffentlicht

Peer-reviewed

Ja

ASJC Scopus Sachgebiete

Werkstoffchemie, Oberflächen, Beschichtungen und Folien, Oberflächen und Grenzflächen

Elektronische Version(en)

https://doi.org/10.3390/coatings12050591 (Zugang: Offen)