Abstract
This paper presents a way of processing cold-sprayed Ti-Al to produce titanium aluminum nitride coatings. These coatings are meant to serve as a durable protective layer on tools exposed to molten aluminum alloys. A Ti-Al powder mixture with a weight ratio of 70/30 was cold sprayed onto specially prepared substrates using nitrogen as a process and powder delivery gas. The resulting coatings were alloyed at different temperatures to obtain a stabilized Ti-Al intermetallic phase for further nitriding treatment. The nitriding process was carried out in an ammonia-nitrogen atmosphere at 900 °C. The final product had a web-shaped microstructure with the same thickness as the cold-sprayed Ti-Al. Test samples were placed in molten aluminum for 1200 hours without notable chemical reaction.
