Low-temperature chemical vapor deposition (CVD) of metallic titanium film from a novel precursor

The metallic Ti film was successfully deposited on the metal substrates at a temperature as low as 620 °C by developing a novel TiCl2 precursor of chemical vapor deposition (CVD) from a Ti-TiCl4 system, much lower than 1140 °C and 1200 °C reported. This is mainly attributed to the unique sublimation and decomposition of TiCl2 at 620 °C. Increasing the deposition temperature above the evaporation temperature of 750 °C accelerated the formation of denser and thicker Ti film. A nearly fully dense Ni-Ti intermetallic film was obtained on the 316 L substrate at 800 °C. This remarkably improves the corrosion resistance of 316 L steel, nearly tripled the pitting potential of deposited 316 L steel. Meanwhile, the microstructure of the 316 L matrix hardly changed, and unexpectedly a strong metallurgical bonding was formed between the deposited layer and substrate due to the minor diffusion of Ni and Fe into Ti film.