Sputter-deposited nitrides for oxidation protection in a steam environment at high temperatures

The oxidation behaviours of ZrN, TiN and TiSiN in a steam environment in the high temperature range of 600 – 900ºC have been studied and compared. Nitride coatings were deposited by reactive magnetron sputtering onto Zirc-alloy and silicon wafer substrates. The steam oxidation test was performed in order to investigate oxidation resistance in the Loss–of–Coolant Accident (LOCA) scenario in Light Water Reactor applications. It was found that TiSiN showed better oxidation resistance in a steam environment than ZrN and TiN. Coatings in the as-deposited state and after thermal exposure were characterised using focused ion beam, transmission electron microscopy and X-ray diffraction to evaluate microstructure and phases present in the coatings