Effect of N2 Flow Rate on Structure and Mechanical Properties of CrN Coatings Prepared by Closed Field Unbalanced Magnetron Sputtering

CrN coatings were deposited by Closed Filed Unbalanced Magnetron Sputtering (CFUMS). The effect of N-2 flow rate on composition, phase components, morphologies and mechanical properties of CrN coatings were studied. The results show that the deposition rate of CrN coatings declined with the increase of nitrogen flow percentage in a Ar/N-2 mixture atmosphere. When the nitrogen flow percentage reached 50% or more, the Cr and N atomic ratio of CrN coatings is close to 1:1. The phase in coatings was the coexistence of Cr, Cr2N and CrN, but the crystal preferred orientation changed significantly with the different N-2 flow rates. The columnar crystal CrN coating with low N-2 flow rate was denser. The hardness and adhension of CrN coatings have no direct relationship with N-2 flow rate.