| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 701413 | Diamond and Related Materials | 2006 | 6 Pages |
The present work explores the deposition of hard, wear resistant multilayer coatings, by magnetron sputtering onto Aluminium (Al) alloy substrates that are used in the automotive industry. Multilayer coatings have been manufactured to increase surface hardness and wear resistance for a commercial powder metallurgy Al alloys (Al 2618). The multilayer coating consisted of 25 bi-layers of Titanium Diboride (TiB2) and diamond-like carbon (DLC). These DLC/TiB2 coatings were fabricated, maintaining a constant composition wavelength (sum of two layers [λ] = 200 nm) for an array of ceramic fractions ranging from 75% to 95% by volume. The effect of the DLC content on the structure and performance (hardness and adhesion) of the films was investigated. The bi-layer thickness influences the failure patterns resulting from the scratch testing. This study has found hardness values of 27.8 GPa, with a critical load of 20 N and a friction coefficient of 0.47. As a result of these findings the multilayer with 10% of DLC was found to be a better compromise between high hardness (23.8 GPa) and high adhesion (critical load higher than 20 N) and with no signs of cracking during friction testing, proving to be a solution to be employed in components located in the upper valve train area of high performance vehicles.
