High hardness coating created by chemical vapor deposition (CVD) technique has been considered in industry, recently. The main goal of applied hard coating is increasing lifetime of industrial parts such as tools and molds. Physical vapor deposition (PVD) and CVD methods are used for coating of hot work tool steels TiN is one of the hard coatings which are created by CVD or PVD methods in order to increase the lifetime of the molds. Plasma assisted chemical vapor deposition (PACVD) is one method of CVD. In this research, a TiN coating applied on H13 hot wok tool steel by PACVD.The substrate temperature in the PACVD is lower than H13 tempering temperature. The main advantage of PACVD method is low deposition temperature. However, the only disadvantage of this method is low deposition rate. In the PVD method, it is necessary the rotation of the parts, during the coating process. Furthermore, it is difficult to coat, the bulk and heavy parts, while the CVD doesn't have this restriction. In this research, effects of PACVD parameters on properties and behavior of TiN coatings was investigated. The TiN coating is created on nitrided and unnitrided H13 in the different deposition temperatures (460, 480 and 510 ). Reactant gases of TiCl4, N2, H2 and Ar in 0.1, 2.5, 1.5, 1.5 mbar pressures are used in coating process. The results show that difference in the deposition temperature and substrate affects on tribological properties. Characterizations of coatings are investigated by thickness, microhardness, nanohardness, chemical composition of coating and morphological measurements and wear behavior .The TiN clusters created on the substrate increase with increasing deposition temperature. Results show that the surface roughness for nitride H13 is 130 nm while for coating is 20 nm. Thus, the coating process reduce roughness and friction coefficient. Young's modulus and hardness of coating created in deposition temperature of 460 was 220 GPa and 1810 HV, respectively. Investigation of tribilogical behavior shows that the dominant mechanisms for coating in high temperature wear are adhesion and tribochemical while in low temperature wear is tribochemical. Key Words : PACVD, TiN, rectant gases, PVD
