MICROSTRUCTURAL AND MICROMECHANICAL CHARACTERIZATION OF A DUPLEX MULTILAYER COATED H13 TOOL STEEL

摘要

Quenched and tempered H13 tool steel was plasma nitrided and PVD coated in a hybrid reactor aiming to obtain a TiN/TiC multi-layer coating deposited on a plasma nitrided substrate, with a more gentle transition of elastic-plastic properties between the outermost layer of the coating and the substrate. Duplex treatment (plasma nitriding and PVD coating) was carried out in a hybrid reactor. Plasma nitriding preceded the DC triode magnetron sputtering PVD process, conducted inside the same chamber, using CH_4 and N_2 as reactive gases. Multi-layer TiN/TiC coatings deposited on a nitrided H13 substrate were obtained. Deposited TiC layers were characterized as containing 18.4 at% and 32.3 at% C, in a cF8 NaCI type unit cell, respectively. The TiN layer showed 41.9 at% N, also in a cF8 NaCI type unit cell. The multi-layer coating showed a gentle transition of elastic-plastic properties assessed by the H/E* and the H~3/E~(*2) ratios and the elastic recovery as a function of the distance from the surface of the specimen. The adhesion of the multi-layered coating to the substrate was greater in the case of the duplex coated specimen compared to the non duplex treated H13 steel.