Thermal and corrosion resistance of nanocomposite gradient TiAlSiN films

This work aims to examine the resistance of nanocomposite TiAlSiN gradient films when exposed in high-temperature dry air and 3 % NaCl aqueous solution environments. This was mainly accomplished by thermogravimetric measurements (non-isothermal and isothermal) and potentiodynamic measurements. The thermal analysis results showed that these samples begin to oxidize at 800 A degrees C, while over 900 A degrees C the oxidation rate increases significantly. Isothermal measurements revealed that at 800 A degrees C the mass gain after 12 h exposure is insignificant and at 900 A degrees C it has very low value. Oxidations performed at higher temperatures resulted in elevated mass gain while a great percentage of the coating was transformed in oxides, which implies that the particular temperature range is out of the working limits of the material. The activation energy was also determined to be 200 kJ mol(-1) from the thermal analysis outcomes. Finally, the as-coated samples were found to have distinguished corrosion resistance in the salt solution compared with the bare substrates and the commonly used TiN coatings.