Sputter deposited low-friction and tough Cr-Si3N4 nanocomposite coatings on plasma nitrided M2 steel

► Nanocomposite coatings of Cr-Si3N4 were prepared by magnetron sputtering on plasma nitrided AISI M2 steel substrates. ► Cr-Si3N4 nanocomposite coating prepared at 48 at.% Cr exhibited hardness of 18 GPa and toughness of 2.0 MPam½. ► At a load of 2 N, Cr-Si3N4 nanocomposite coating (48 at.% Cr) exhibited an average friction coefficient of 0.30.