Tribological Characteristics of a-C:H:Si and a-C:H:SiOx Coatings Tested in Simulated Body Fluid and Protein Environment.

Anna Jedrzejczak,Anna Sobczyk-Guzenda,Damian Batory,Witold Szymanski,Jacek Grabarczyk,Witold Kaczorowski,Lukasz Kolodziejczyk,Piotr Niedzielski,Agnieszka Kolodziejczyk

doi:10.3390/ma15062082

Abstract

This paper presents the tribological properties of silicon and oxygen incorporated diamond-like carbon coatings tested in simulated body fluid and bovine serum albumin environments. The tests were performed using a ball-on-disc tribometer with an AISI316L steel counterbody. The wear tracks and wear scars were analyzed using optical microscopy and a nanoindenter. The interaction between the coating and the working environment was analyzed by Fourier transform infrared spectroscopy, whereas changes in the chemical structure before and after the tribological tests were compared with the use of Raman spectroscopy. Our study showed that the tribological parameters are governed by the presence of oxygen rather than the changing concentration of silicon. Both of the spectroscopy results confirm this statement, indicating that coatings with low concentrations of silicon and oxygen appear to be better candidates for biological applications in terms of wear resistance.

Highlights

Wear is a critical issue in the design of medical implants, in load bearing applications such as knee and hip joint prosthesis
In our work we present the effect of silicon and oxygen admixture on the friction and wear behavior of silicon-incorporated diamond-like carbon (DLC) coatings tested in simulated body fluid (SBF) and bovine serum albumin (BSA) environments
Our previous papers related to DLC coatings doped with silicon using HMDSO revealed that high negative self-bias potentials during the deposition improve the quality of the silicon-incorporated coatings [22]

Summary

Introduction

Wear is a critical issue in the design of medical implants, in load bearing applications such as knee and hip joint prosthesis. The surface of medical implants must be tolerant to dynamic loading and long-term exposure to biological interaction with surrounding tissue [1,2]. Both may induce severe degradation of the material and the implant as well. Technological surface layers with increased wear resistance are formed by the appropriate selection of materials for the elements of the joints, characterized by increased hardness, a low coefficient of friction (COF), and good corrosion resistance. An excellent combination of properties desired in the biomedical engineering field have prompted scientists to look for ways to eliminate them This has been reflected in the still increasing number of papers concerning the doping of these coatings with other elements, e.g., Si, Ag, Ti, Cu [15–19]

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