Effects of substrate bias on the structure and mechanical properties of (Al1.5CrNb0.5Si0.5Ti)Nx coatings

► Films of (Al1.5CrNb0.5Si0.5Ti)Nx were prepared by reactive magnetron sputtering. ► Effect of substrate bias on films structure and mechanical properties was studied. ► A 200% of hardness increase was found by increasing the substrate bias. ► The mechanisms of hardness enhancement were discussed and clarified in this study.