Evaluation of wear resistance of AlSiTiN and AlSiCrN nanocomposite coatings for cutting tools

Nanocomposite coatings, consisting of nanocrystalline AlTiN or AlCrN dispersed in a matrix of amorphous Si3N4 were deposited onto hard metal substrates via cathodic arc PVD. Coating thickness, adhesion properties and hardness have been measured. Wear resistance was measured via tribological tests and the main wear phenomena were studied using SEM-EDS. The coatings have then been functionally tested as cutting tool coatings for WC mills for high speed, drymilling operation on AISI M2, a difficult to cut die steel. Cutting performances and laboratory results have been discussed, together with wear mechanisms, in light of the comparison with commercial nitride-coated tools.