The Effect of Bias Voltage and Gas Pressure on the Structure, Adhesion and Wear Behavior of Diamond Like Carbon (DLC) Coatings With Si Interlayers

Abstract

Abstract:In this study diamond like carbon (DLC) coatings with Si interlayers were deposited on 316L stainless steel with varying gas pressure and substrate bias voltage using plasma enhanced chemical vapor deposition (PECVD) technology. Coating and interlayer thickness values were determined using X-ray photoelectron spectroscopy (XPS) which also revealed the presence of a gradient layer at the coating substrate interface. Coatings were evaluated in terms of the hardness, elastic modulus, wear behavior and adhesion. Deposition rate generally increased with increasing bias voltage and increasing gas pressure. At low working gas pressures, hardness and modulus of elasticity increased with increasing bias voltage. Reduced hardness and modulus of elasticity were observed at higher gas pressures. Increased adhesion was generally observed at lower bias voltages and higher gas pressures. All DLC coatings significantly improved the overall wear resistance of the base material. Lower wear rates were observed for coatings deposited with lower bias voltages. For coatings that showed wear tracks considerably deeper than the coating thickness but without spallation, the wear behavior was largely attributed to deformation of both the coating and substrate with some cracks at the wear track edges. This suggests that coatings deposited OPEN ACCESSCoatings 2014, 4 215 under certain conditions can exhibit ultra high flexible properties.

DLC Films Grown On Steel Using An Innovator Active Screen System For PECVD Technique

“…For both samples group, films adhesion increased almost linearly according to the bias voltage increase during silicon interface deposition. Similar results of enhanced adhesion were also obtained by Ward 22 . When films adhesion is compared for each system, a much higher performance was observed for the samples grown in active screen system, as presented in Table 2.…”

Probing fatigue resistance in multi-layer DLC coatings by micro- and nano-impact: Correlation to erosion tests

“…values of both H/E and H 3 /E 2 (0.042 and 0.017 GPa respectively). The mechanical properties of the SS substrate are similar to that recorded by Ward et al[62] prior to coating with a-C:H with Si interlayer. The hardness of the HTS after hardening is similar to that seen by Wilbur et al[63] though a nitriding processing was used compared to the flame hardening for this study.…”

Tribological performance of graphite-like carbon films with varied thickness

“…One of the reasons could be attributed to the diversity of the internal structure of GLC samples, where the sp 3 hybrid carbon atoms were commonly considered to be responsible for the high hardness and the rich sp 2 bond structure were reported to demonstrate an excellent wear resistance [13]. Deposition parameters such as target currents [10], substrate bias [14,15] and power densities [9,15,16], are the most common adjustable variables used to optimize the structure and properties of amorphous carbon films. For example, Wang et al [10] reported that the relative content of sp 2 and sp 3 hybridisation (ID/IG) changed from 1.5 to 3.0 with the increase of target current from 0.4 A to 2.0 A, while the hardness and film compactness decreased.…”