Ternary and quarternary TiBN and TiBCN nanocomposite coatings deposited by arc ion plating

Binary TiN monolayer coating cannot meet the demands of the industrial application. a route for improving its performance is the addition of new element: silicon, boron or carbon. Therefore the main objective of this work is the preparation of TiBN and TiBCN coatings with a nanocomposite structure offering a higher micro-hardness as well as an improved wear resistance. Arc ion plating was used for the deposition of the TiBN and TiBCN coatings on Si (100) and cemented carbide substrates. TiBN nanocomposites coatings was deposited using TiB2 composite target in pure N2 whereas for TiBCN coatings was in mixed C2H2 and N2. The components, microstructure and mechanical properties behavior of the nanocomposite coatings were investigated. TiBN coatings consisted of the crystalline phases TiN, TiB2 and amorphous BN. A maximum micro-hardness of about 3160 HV was observed at a 0.5 Pa N2 pressure while the micro-hardness correlates well with N2 pressure. TiBCN coatings prepared with the N2 and C2H2 process exhibit a nanocomposite structure of nanocrystalline TiN and TiB2, morphous C, CN and BN. Compared to TiBN, lower micro-hardness of the TiBCN coatings down to 1761 HV was measured for at 1/2 gas flow ratio of C2H2 and N2. For grinding material cemented carbide, the friction coefficient of TiBN coating was nearly 0.4 while the friction coefficient of TiBCN coatings was lower 0.2 with the increasing of C2H2 and N2 flow ratio.