Abstract
DLC films cover a wide range of different carbon based
coatings, starting from soft to extremely hard
diamond-like carbon films. In this study two different
types of DLC films have been studied in respect of their
stress and strain characteristics and tribological
performance. The coatings are hydrogenated amorphous
carbon (a-C:H) coatings deposited by PECVD and
tetrahedral amorphous carbon (ta-C) coating deposited by
filtered arc technique. In order to evaluate the
mechanical behaviour of the coatings under load, 3D FE
modelling was carried out in combination with scratch
testing. Also the tribological performance was evaluated
with pin-on-disc tests using stepwise increasing normal
load. The 3D FEM model was developed for calculating the
stress and strain distributions of DLC coated systems and
to evaluate how coating thickness and elastic properties
affect the stress-strain state at crack initiation
location. The simulation was compared to the findings to
experimental observations in scratch test contact
conditions, when the spherical diamond tip was moving
with increased load on a coated surface. The coating
performance was evaluated with scratch testing to detect
the crack generation as well as the coating adhesion.
When combining the simulated coating characteristics with
empirical observation of coating fracture patterns the
coating fracture performance and tolerance to cracking
could be evaluated. A major effect of the coating elastic
modulus on the stress and fracture behaviour of the
coatings was observed. In the tribological testing the
both coatings had a low friction performance. In the
tribological testing with stepwise increasing load, the
critical load for coating delamination was higher for the
a-C:H coating, which is in accordance with the results of
FE modelling of coating stress state.
Original language | English |
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Publication status | Published - 2012 |
MoE publication type | Not Eligible |
Event | 15th Nordic Symposium on Tribology, NORDTRIB 2012 - Trondheim, Norway Duration: 12 Jun 2012 → 15 Jun 2012 Conference number: 15 |
Conference
Conference | 15th Nordic Symposium on Tribology, NORDTRIB 2012 |
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Abbreviated title | NORDTRIB 2012 |
Country/Territory | Norway |
City | Trondheim |
Period | 12/06/12 → 15/06/12 |
Keywords
- DLC
- ta-C
- a-C:H
- tribology
- modelling
- ProperTune