Influence of chromium buffer layer on Cr/ta-C composite films

Abstract

Cr buffer layers of six different thicknesses (100, 200, 300, 400, 500 and 600 nm) were respectively deposited on silicon substrate so as to constitute a series of Cr implantation layer/Cr buffer layer/tetrahedral amorphous carbon (ta-C) films. Analysis by SEM suggests that the implantation of Cr layer favourably improves the interfacial transition between ta-C film and Si substrate. X-ray diffraction detection reveals that the difference in thickness of Cr buffer layer does not significantly influence the crystalline structure. Raman result shows that the ductility of Cr buffer layer favours to remit stress of the ta-C film. Increase in Cr buffer layer thickness results in the reduction of nanohardness value. However, its elastic modulus and adhesion exhibit an initial increase followed by a decreasing fluctuation. Result of the study shows the accomplishment of superior mechanical properties for the ta-C film with 200 nm thick Cr buffer layer.

Effect of Ti Transition Layer Thickness on the Structure, Mechanical and Adhesion Properties of Ti-DLC Coatings on Aluminum Alloys

“…However, as t 0 increases continuously, the residual compressive stress slowly increases, which may be the consequence of an increase in thermal stress in the coating. The results show that suitably changing the Ti transition layer thickness can effectively adjust residual compressive stress of coatings, which agrees with the report of Liu et al [ 25 ]. Moreover, we found that as the value of t 0 increases, the measured values of hardness and elastic modulus exhibit a decreasing tendency.…”

“…Furthermore, mutual diffusion of Ti and C elements at the layer inter interfacial boundary of the substrate, the Ti layer and the Ti-DLC layer, is clearly recognized ( Figure 3 b–e). This diffusion results in a distribution gradient effect near the interface of the layer and serves to enhance the interfacial adhesion of the coating [ 25 ].…”