Microstructure control in TiAlN/SiNx multilayers with appropriate thickness ratios for improvement of hardness and anti-corrosion characteristics

► Crystalline SiNx grew coherently with TiAlN, improving the hardness of coating. ► Densified microstructure with amorphous SiNx exhibited higher corrosion resistance. ► Tunable properties in coatings were obtained through the structure control of SiNx.