Erosion wear of CrN, TiN, CrAlN, and TiAlN PVD nitride coatings

Four nitride coatings (CrN, ZrN, CrAlN, and TiAlN) were deposited on YT15 cemented carbide by cathode arcevaporation technique. Microstructural and fundamental properties of these nitride coatings were examined. Erosion wear tests were carried out, the erosion wear of these nitride coatings caused by abrasive particle impact was compared by determining the wear depth and the erosion rates of the coatings. The wear surface features were examined by scanning electron microscopy. Results showed that the coatings with Al (CrAlN and TiAlN) exhibited higher erosion wear resistance over those without Al (CrN and TiN). The H-3/E-2 of the coating seemed to play an important role with respect to its erosion wear in erosion tests. AlTiN and CrAlN coatings being with high H-3/E-2 exhibited lower erosion rates, while CrN coating with low H-3/E-2 showed higher erosion rates under the same test conditions. Analysis of eroded surface of the coatings demonstrated that the TiN and CrN coatings exhibited a typical brittle fracture induced removal process, while AlTiN and CrAlN coatings showed mainly micro cutting and cycle fatigue fracture of material removal mode. (C) 2012 Elsevier Ltd. All rights reserved.