Nanocomposite nc-TiAlSiN and nc-TiN-BN coatings:: their applications on substrates made of cemented carbide and results of cutting tests

Nanocomposite coatings TiAlSiN and Ti/BN were deposited on indexable cutting inserts, made of cemented carbide, by plasma vapor deposition (PVD) and combined PVD/plasma activated chemical vapor deposition (PACVD) techniques. The Ti/BN coatings were prepared in two superhard forms: (1) TiN-BN nanocomposites with low residual internal stress and with the presence of a c-BN phase as determined by XRD and (2) superhard Ti-B-N coatings with very high residual internal stress and with only one crystalline phase detected by XRD. Their properties were evaluated. Nanocomposite monolayer TiAlSiN. nanocomposite multilayer TiAlSiN and Ti-B-N layer applied on the indexable inserts were compared in cutting tests. The nanocomposite multilayer TiAISiN showed the best performance under conditions of high cutting speed, whereas the Ti-B-N coatings were more successful at lower cutting speed. (C) 1999 Elsevier Science S.A. All rights reserved.