In this research, the high temperature oxidation and corrosion resistance of TiN-TiAlN double coating and TiN-TiAlN-CrAlN triple coating applied by duplex process of plasma nitriding and cathodic arc physical vapor deposition (Arc-PVD) on the H13 hot-work tool steel substrate were studied in the absence and presence of molten aluminum at 850 C for 18 h. Nanohardness indentation was performed to obtain the hardness and elastic modulus of the coatings. Scanning electron microscope (SEM) equipped with an energy-dispersive x-ray spectroscopy (EDS) was employed to observe the morphology and analyze the elemental composition of the samples before and after high temperature oxidation and corrosion experiments. Phase composition analysis was investigated using x-ray diffraction (XRD) patterns. The results indicated that the weight loss of the TiN-TiAlN and TiN-TiAlN-CrAlN coatings were 42 and 45% lower than that of the uncoated H13 steel in the oxidative environment at 850 C, respectively. Also, the thickness loss of the TiN-TiAlN and TiN-TiAlN-CrAlN coatings were obtained to be 61 and 47% lower than that of the uncoated H13 steel in the molten aluminum at 850 C, respectively. Overall, the results declared the greater stability of TiN-TiAlN-CrAlN triple coating in high temperature oxidation and corrosion in molten aluminum compared to the TiN-TiAlN double coating.

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