Abstract
Hydrogen-free diamond-like carbon (DLC) thin films are attractive for a wide range of industrial applications. One of the challenges related to the use of hard DLC lies in the high intrinsic compressive stresses that limit the film adhesion. Here, we report on the mechanical and tribological properties of DLC films deposited by High Power Impulse Magnetron Sputtering (HiPIMS) with Ne as the process gas. In contrast to standard magnetron sputtering as well as standard Ar-based HiPIMS process, the Ne-HiPIMS lead to dense DLC films with increased mass density (up to 2.65 g/cm3) and a hardness of 23 GPa when deposited on steel with a Cr + CrN adhesion interlayer. Tribological testing by the pin-on-disk method revealed a friction coefficient of 0.22 against steel and a wear rate of 2 × 10−17 m3/Nm. The wear rate is about an order of magnitude lower than that of the films deposited using Ar. The differences in the film properties are attributed to an enhanced C ionization in the Ne-HiPIMS discharge.
Highlights
Hydrogen-free diamond-like carbon (DLC) thin films exhibit properties that make them suitable for a wide range of applications, from biomedical implants to engine components
We have demonstrated that the Ne-High Power Impulse Magnetron Sputtering (HiPIMS) process leads to DLC films with significantly improved structural and mechanical properties, compared to the corresponding
The improved properties of the Ne-HiPIMS DLC films were attributed to an enhanced C ionization in the Ne discharge
Summary
Hydrogen-free diamond-like carbon (DLC) thin films exhibit properties that make them suitable for a wide range of applications, from biomedical implants to engine components. Limited thermal stability and inadequate mechanical strength inhibit the use of sputter-deposited DLC films in high-end wear-resistant and tribological applications. The successful implementation of DLC films in these applications requires hard and dense DLC films with low compressive stresses and high thermal stability, which is not possible with state-of-the-art methods. The authors previously exploited the ion-induced stress relaxation in the post-thermal spike regime using pulsed ionized flux to produce high density and low compressive stress DLC films [15]. DLC films with a high mass density of 2.7 g/cm and low compressive stresses (2.5 GPa) were produced. In this work, detailed investigations on the mechanical and tribological properties of the high density and low-stress DLC films produced by Ne-HiPIMS discharge are made. In order to put the findings into the state-of-the-art perspective, the plasma and film properties are compared with the standard Ar-HiPIMS DLC films
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
