Next Article in Journal
Mechanical and Electroconductive Properties of Mono- and Bilayer Graphene–Carbon Nanotube Films
Previous Article in Journal
Electrochemical Stability Enhancement in Reactive Magnetron Sputtered VN Films upon Annealing Treatment
Previous Article in Special Issue
Cracking, Microstructure and Tribological Properties of Laser Formed and Remelted K417G Ni-Based Superalloy
Open AccessArticle

Towards Functional Silicon Nitride Coatings for Joint Replacements

1
Division of Applied Materials Science, Department of Engineering Sciences, Uppsala University, Uppsala 752 37, Sweden
2
IHI Ionbond AG, Industriestrasse 211, Olten 4600, Switzerland
3
Thin Film Physics Division, Department of Physics, Chemistry and Biology (IFM), Linköping University, Linköping 581 83, Sweden
*
Author to whom correspondence should be addressed.
Coatings 2019, 9(2), 73; https://doi.org/10.3390/coatings9020073
Received: 30 November 2018 / Revised: 14 January 2019 / Accepted: 18 January 2019 / Published: 25 January 2019
(This article belongs to the Special Issue Tribology and Surface Engineering)
  |  
PDF [1618 KB, uploaded 28 January 2019]
  |  

Abstract

Silicon nitride (SiNx) coatings are currently under investigation as bearing surfaces for joint implants, due to their low wear rate and the good biocompatibility of both coatings and their potential wear debris. The aim of this study was to move further towards functional SiNx coatings by evaluating coatings deposited onto CoCrMo surfaces with a CrN interlayer, using different bias voltages and substrate rotations. Reactive direct current magnetron sputtering was used to coat CoCrMo discs with a CrN interlayer, followed by a SiNx top layer, which was deposited by reactive high-power impulse magnetron sputtering. The interlayer was deposited using negative bias voltages ranging between 100 and 900 V, and 1-fold or 3-fold substrate rotation. Scanning electron microscopy showed a dependence of coating morphology on substrate rotation. The N/Si ratio ranged from 1.10 to 1.25, as evaluated by X-ray photoelectron spectroscopy. Vertical scanning interferometry revealed that the coated, unpolished samples had a low average surface roughness between 16 and 33 nm. Rockwell indentations showed improved coating adhesion when a low bias voltage of 100 V was used to deposit the CrN interlayer. Wear tests performed in a reciprocating manner against Si3N4 balls showed specific wear rates lower than, or similar to that of CoCrMo. The study suggests that low negative bias voltages may contribute to a better performance of SiNx coatings in terms of adhesion. The low wear rates found in the current study support further development of silicon nitride-based coatings towards clinical application. View Full-Text
Keywords: silicon nitride; coating; reactive high-power impulse magnetron sputtering; wear; joint replacements silicon nitride; coating; reactive high-power impulse magnetron sputtering; wear; joint replacements
Figures

Figure 1

This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited (CC BY 4.0).
SciFeed

Share & Cite This Article

MDPI and ACS Style

Filho, L.; Schmidt, S.; Leifer, K.; Engqvist, H.; Högberg, H.; Persson, C. Towards Functional Silicon Nitride Coatings for Joint Replacements. Coatings 2019, 9, 73.

Show more citation formats Show less citations formats

Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Related Articles

Article Metrics

Article Access Statistics

1

Comments

[Return to top]
Coatings EISSN 2079-6412 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top