Regulatory mechanism of N2 flow rate on structure and properties of CrAlNiYN coatings by FCVA technique

Abstract

In this work, a novel CrAlNiYN coating was prepared by filter cathode vacuum arc (FCVA) technique. The evolution of the microstructure and properties of the coatings with varying N2 flow rates was systematically investigated. The results revealed that as the N2 flow rate increased from 10 to 90 sccm, the N content in the coating increased from 2.54 to 46.20 at.%, while the Ni content significantly decreased from 67.54 to 31.15 at.%. Simultaneously, the phase structure transitioned from the intermetallic compound AlNi3 to the solid solution Al(Cr)N. This transformation, along with solid solution strengthening and grain refinement, resulted an increase in hardness from 13.4±0.4 to 26.6±0.6 GPa. Moreover, the H/E, H3/E2 and We values also displayed a gradually increasing trend, indicating improved resistance to plastic deformation. However, the adhesion strength presented a weakening trend from HF1 to HF3. Furthermore, the corrosion current density of coatings first increased and then slightly decreased with the increase of N2 flow rate, while the polarization resistance had the opposite trend of change. Among them, the coating at 10 sccm exhibited the best corrosion resistance, with the lowest icorr of 0.150 μA∙cm-2 and the highest Rp of 302.1 kΩ∙cm2.