On the dependence of mechanical and tribological properties of sputtered chromium nitride thin films on deposition power

In the past decade, Al 5083 has attracted considerable attention due to its promising potential applications in military vehicles. This paper reports the improvement of mechanical and tribological properties of Al 5083 coated with chromium nitride. Chromium nitride thin films were deposited by DC magnetron sputtering technique on Al 5083 substrate at different deposition powers (150 to 300 W in steps of 50 W). A FESEM was used for surface morphology and chemical composition studies. The thickness of the films was determined by quartz crystal monitor and checked with FESEM cross-section images. Films thickness was 2 +/- 0.01 mu m for all samples. The mechanical and tribological properties were investigated by nano-indentation and scratch tests, respectively. The results showed that grains size decreases with the deposition power, while the samples produced at higher powers had a denser structure. The results also showed that by increasing the deposition power film hardness increased and the friction coefficient and scratch volume decreased.