Studies Of Preparation And Properties Of Corrosion Of CrN Thin Films Deposited By Cathode Arc

Cathode arc has been extensively used to deposit various coatings such as TiN, CrN due to its higher ionization, higher deposition rate and strong adhesion with substrate.The single-layer and multi-layer CrN coating have been deposited by cathode arc technigue in this paper. The microstructure, micro-hardness, morphology, tribology and corrosion properties were analyzed. The influences of deposition parameters such as content of nitrogen, bias voltage, arc current, substrate temperature on the properties and structure of the coatings was analyzed.The phase composition of the single layer CrN_x is CrN and Cr₂N. With the increasing of content of nitrogen, the intense of diffraction peak of Cr₂N(211) decreases and the intense of the phase CrN(220) increases. As a result, the ratio of these two compositions decreas and the atom ratio of N to Cr increas. With the increasing of content of N₂ , the depositon ratio of coating decreas, the macro-particle on the surface of coating decreas too. And the morphology is smooth. The micro-hardness of CrN_x shows two peaks versus to single phase of Cr₂N and CrN. The lower micro-hardness appearance of two kind of phase of Cr₂N and CrN. Take consideration of main influences of micro-hardness and morphology on the tribology of the coatings, the coatings shows higher micro-hardness, surface quality, fine tribology and corrosion with nitrogen content of 35%.For the multi-lay Cr/CrN, the phase is composed of CrN,Cr₂N and Cr. The priority is Cr₂N(111). The sandwich structure is obtained as Cr layer-transition-layer-CrN layer, and Cr/CrN(5/10min) shows good properties of corrosion in the solvent of 3.5% NaCl. The one by one layers of hardness and soft not only disperse the inner-stress, but also increasing adhesion strongtly and increasing the corrosion .