Effects of Nitrogen Modification of Porous PVD–MoS2 Coatings on the Tribological Behavior under Rolling–Sliding Conditions in Vacuum
Seynstahl A, Polzer M, Bartz M, Wartzack S, Tremmel S (2023)
Publication Language: English
Publication Type: Journal article
Publication year: 2023
Journal
Book Volume: 11
Pages Range: 335
Issue: 8
URI: https://www.mdpi.com/2075-4442/11/8/335
DOI: 10.3390/lubricants11080335
Open Access Link: https://doi.org/10.3390/lubricants11080335
Abstract
In order to improve the tribological performance of PVD–MoS2 coatings, which are frequently used as a solid lubricant for operating in challenging environments, e.g., in a vacuum, they can be modified with nitrogen. This work evaluates the tribological behavior and a possible compaction occurring during the initial tribological load in the rolling contact for pure and nitrogen-modified PVD–MoS2 coatings in a vacuum. Short-running tests (1000 cycles) of coated steel discs paired with uncoated steel discs made from 100Cr6 (1.3505, AISI 52100) were conducted on a two-disc tribometer. The slide-to-roll ratio of 10.5% was kept constant, while the load was varied in two steps from 1.1 GPa to 1.6 GPa. Subsequently, a comparison was made between the worn and the pristine coatings by means of nanoindentation and an optical analysis of the wear track. The formation of a load-bearing solid lubrication was achieved for both MoS2-variants. The main differences affected the material transfer and wear mechanisms. The worn coatings reached a similar wear coefficient of 4 × 10−6 mm3N−1m−1 and a possible compaction of the coatings was found, indicated through an increased indentation hardness (for MoS2 1158% and MoS2:N 96% at a 1.1 GPa load). The assumed tribological mechanism changed with nitrogen modification, but scales with increasing load. The nitrogen-modified MoS2 coating showed less compaction than pure MoS2, while the frictional behavior was improved by a 17°% reduction of the coefficient of friction.
Authors with CRIS profile
Markus Polzer
Chair of Engineering Design
Marcel Bartz
Chair of Engineering Design
Sandro Wartzack
Chair of Engineering Design
Involved external institutions
Germany (DE)How to cite
APA:
Seynstahl, A., Polzer, M., Bartz, M., Wartzack, S., & Tremmel, S. (2023). Effects of Nitrogen Modification of Porous PVD–MoS2 Coatings on the Tribological Behavior under Rolling–Sliding Conditions in Vacuum. Lubricants, 11, 335. https://doi.org/10.3390/lubricants11080335
MLA:
Seynstahl, Armin, et al. "Effects of Nitrogen Modification of Porous PVD–MoS2 Coatings on the Tribological Behavior under Rolling–Sliding Conditions in Vacuum." Lubricants 11 (2023): 335.
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