Improved Tribological Performance of ta-C/MoSx Coatings Deposited on Laser Micro-Structured Steel Substrates in Both Vacuum and Air

Vacuum and air atmospheres impose very different requirements on tribological-loaded contacts, which usually require different surface materials. While hard tetrahedral amorphous carbon (ta-C) coatings provide good tribological properties in air, soft coatings such as molybdenum disulfide (MoS2) wor...

Full description

Saved in:
Bibliographic Details
Published in:Lubricants 2024-06, Vol.12 (6), p.200
Main Authors: Makowski, Stefan, Härtwig, Fabian, Soldera, Marcos, Ojeil, Mahmoud, Lorenz, Lars, Kaulfuß, Frank, Lasagni, Andrés Fabián
Format: Article
Language:English
Subjects:
Amorphous materials
Arc deposition
Atmosphere
Carbon
Coatings
Contact pressure
direct laser interference patterning
DLC
Friction
Hydrogen
Lasers
Lubricants & lubrication
Mechanical properties
Molybdenum
Molybdenum disulfide
MoS2
Nitrogen
Protective coatings
Raman spectroscopy
Space applications
Steel
Substrates
ta-C
Temperature
Tribology
vacuum
Citations: Items that this one cites
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Vacuum and air atmospheres impose very different requirements on tribological-loaded contacts, which usually require different surface materials. While hard tetrahedral amorphous carbon (ta-C) coatings provide good tribological properties in air, soft coatings such as molybdenum disulfide (MoS2) work well in a vacuum. Tribological performance in the respective other environment, however, is poor. In this work, the combination of laser microstructured (direct laser interference patterning) steel substrates and the deposition of ta-C and MoSx coatings with vacuum arc evaporation (LaserArc™) was studied, resulting in steel/DLIP, steel/DLIP/ta-C, steel/DLIP/MoSx, steel/DLIP/ta-C/MoSx, and steel/MoSx surface combinations. The tribological properties were studied using a ball-on-disk tribometer with a steel ball counter body in air and in a vacuum (p < 5 × 10−7 mbar). The type of the topmost coating governed their tribological properties in the respective atmosphere, and no general beneficial influence of the microstructure was found. However, steel/DLIP/ta-C/MoSx performed best in both conditions and endured the highest contact pressure, which is attributed to the mechanical support of the ta-C coating and MoSx reservoir in the remaining structure, as evidenced by Raman spectroscopy. The findings suggest that such combination allows for surfaces bearing a high load capacity that can be applied in both a vacuum and in air, for example, in multi-use space applications.
ISSN:2075-4442
2075-4442
DOI:10.3390/lubricants12060200