Characteristics of PVD-CrAlSiN films after post-coat heat treatments in nitrogen atmosphere

In this study, the CrAlSiN films were first synthesized using the cathodic arc evaporation system with Cr (99.99 at.%) metal and Al88Si12 alloy dual cathodes. The films then underwent heat treatments at different temperatures of 400, 600, and 800 °C for 3 h in a nitrogen atmosphere. Microstructures of the heat-treated films were analyzed with X-ray photoelectron spectroscopy, X-ray diffractometer, and scanning electron microscopy. The mechanical properties of the films were explored via the Rockwell indentation test, the nano-indentation test, the ball-on-disc tribological test, and the cutting test. The results show that the CrAlSiN film heat-treated at 600 °C has the highest hardness, lowest friction coefficient, and the best wear resistance among the tested films (with or without heat-treatments). Moreover, the film, after being heated at 600 °C, could provide an optimal machining performance for the cutting test.