Enhancement of toughness and wear resistance by CrN/CrCN multilayered coatings for wood processing

The coatings applied onto woodworking tools must possess higher hardness, adhesion, and fracture toughness. The CrN/CrCN multilayered coatings are deposited on M2 high-speed steel (HSS) and Si (100) by cathodic arc evaporation with different C2H2 flow rates and characterized systematically. The addition of carbon to the CrN coatings can enhance the toughness of coatings and the H/E ratio. The H/E and H3/E2 ratios reach 0.085 and 0.176, respectively. The maximum nanohardness of the coatings is 24 GPa and the smallest friction coefficient is 0.48 together with the higher adhesion between the coating and substrate (HF1). Larger C2H2 flow rate can produce porous and loose microstructure with poor mechanical properties. The lifetime of the CrN/CrCN-coated blades made of high speed steel and cemented carbide materials is increased by about 33% and 7% respectively compared to that of CrN-coated blades, and by 170% and 110% compared to that of uncoated blades.