Size effect in the titanium/diamond‐like carbon bilayer films: effect of relative thickness on their structure and mechanical properties

Abstract

Titanium/diamond‐like carbon (Ti/DLC) bilayer films with different relative thickness were fabricated by direct‐current and pulsed cathode arc plasma method. Microstructure, morphological characteristics, and mechanical properties of the films were investigated in dependence of the thickness of Ti and DLC layers by Raman spectroscopy, atomic force microscopy, Knoop sclerometer, and surface profilometer. Raman spectra of Ti/DLC bilayers show the microstructure evolution (the size and ordering degree of sp2‐hybridized carbon clusters) with varying the thicknesses of Ti interlayer and DLC layer. Nano‐scaled Ti interlayer of 12–20 nm thickness presents the largest size effect. The catalytic effect of the sublayer is most pronounced in the carbon layer of less than 106 nm. In these thickness ranges, the bilayer films possessed the highest micro‐hardness and reactivity between atoms at interface. Internal stress in the bilayer monotonically decreases, with the thickness of Ti interlayer increasing to 30 nm and then becomes stable with the thickness. These results are associated with the occurrence of atomic diffusion process at Ti/C interface, and they are of cardinal significance to optimize the structure and mechanical properties of carbon‐based multilayer films. Copyright © 2016 John Wiley & Sons, Ltd.

NANOSTRUCTURED Ti-C THIN FILMS DEPOSITED BY THERMIONIC VACUUM ARC (TVA) TECHNOLOGY

“…In the case of sample A6 and A8 with the thickness of 16nm Ti layers, the predominance of cubic TiC phase in both cases can be explained by intensifying the diffusion processes at Ti/C interfaces, in comparision with samples A5 and A7, as a result of the decrease of the thickness of Ti layers at 16nm. This ascertainment is consistent with reference [8]. The authors of study [8] present titanium/diamond-like carbon bilayer films with different relative thickness fabricated by direct-current and pulsed cathode arc plasma method, showing the microstructure evolution (the size and ordering degree of sp 2hybridized carbon clusters) with varying the thickness of Ti interlayer.…”

“…The authors of reference [8] presented Titanium/Diamond like carbon bilayer films with different relative thickness which were synthesized by direct current and pulsed cathode arc plasma method. The studies show the microstructure evolution with varying the thicknesses of Ti interlayer and Diamond like carbon layer.…”

Boron-Carbon Coatings: Structure, Morphology, and Mechanical Properties

“…In contrast, the coating is characterized by high mechanical properties provided that ID/IG ≤ 1. It was shown in [20,22] that an increase in the ID/IG ratio and a shift of the G peak to the region of lower wavenumbers in comparison with the peak position for the a-C coating determine a decrease in the degree of structural ordering of Csp 3 carbon clusters. Subsequently, it can be concluded that the shift in the G-peak position with a slight increase in the ID/IG ratio values, which is characteristic of the ɑ-C coatings with boron concentrations of 2.3 and 17.4 at.…”

“…5). The spectra of photoelectron states obtained with a high resolution and describing the chemical bonds characteristic of each element in the coating, namely the C1s peak (at 284.8 eV), the B1s (191 eV) and O1s (538 eV) peaks were subjected to further analysis [20,21]. with the presence of more than one heterophase in the coating (carbon, carbide) [42,43].…”

“…To create composite coatings, doping with elements such as silicon [15], fluorine [16] and nitrogen [17,18], as well as metals: chromium [19] and titanium [19][20][21] is widely used. When metallic elements are included in the structure of a-C coatings, as a rule, metal carbides are formed, distributed in the volume of the amorphous carbon matrix.…”