Design of nano-scale multilayered nitride hard coatings deposited by arc ion plating process: Microstructural and mechanical characterization

Abstract

The objective of the present study was to investigate some transition metal nitride to determine the relationship between microstructural evolution and mechanical properties such as hardness and adhesion strength of the hard coating. Results showed that it was possible to form nano-scale multilayers of Ti(CuNiZr)N/AlCr(SiW)N with chemical fluctuation of Ti-rich and Al-rich nitrides. It was believed that these nano-scale multilayers with chemical fluctuation could form during table rotation of the arc ion plating process, causing difference in mean free path of chemical elements from the target. Microstructural investigation confirmed that the multilayer consisted of three layers with nanostructured periodic stripe patterns on the multilayer coating based on detailed individual layers analysis. Furthermore, Ti(CuNiZr)N/AlCr(SiW)N multilayer showed mechanical properties, including hardness of 36.0 ± 3 GPa and adhesion strength represented by the critical load of 93 ± 5 N with the highest H/E and H3/E2 ratios.

Keywords

• Arc ion plating
• Microstructure
• Nitride hard coating
• Multilayer
• Hardness
• Adhesion strength