Toughness enhancement in highly NbN-alloyed Ti-Al-N hard coatings

Obtaining high hardness combined with enhanced toughness represents one of the current challenges in material design of hard ceramic protective coatings. In this work, we combine experimental and ab initio density functional theory (DFT) analysis of the mechanical properties of Ti-Al-Nb-N coatings to validate the results of previous theoretical investigations predicting enhanced toughness in TiAlN-based systems highly alloyed (>25 at. %) with...