Effect of Aluminum Addition to Nb-Al-C-N Coatings on AISI M2 Steel Obtained by Thermo-Reactive Deposition Technique

Abstract

In this study, aluminum-doped (1 and 2 wt.%) and Al-free niobium carbo-nitride coatings were applied to the surface of AISI M2 high speed steel using the process of thermo-reactive deposition technique (TRD) at 1000 degrees C during 1-4 h. The obtained coatings were characterized by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD) analysis and micro hardness test. Nb-Al-C-N layers were compact and homogeneous. X-ray diffraction analysis has shown that the major phases formed in the coating layer are Nb2CN and NbN. The depth of the coating layer had increased with the treatment time and ranged from 6.65 to 9.05 mu m. The measured values of the hardness of the coating layers were ranging between 2136 and 2636 HK0.005.