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INVESTIGATION OF TITANIUM NITRIDE SYNTHESIZED BY ION BEAM ENHANCED DEPOSITION ZHOU JIANKUN, LIU XIANGHUAI, CHEN YOUSHAN, ZHENG ZHIHONG, HUANG WEI, ZHOU ZUYAO, ZOU SHICHANG Ion Beam Laboratory, Shanghai Institute of Metallurgy, Academia Sinica, Shanghai 200050, China ABSTRACT Titanium nitride films have been synthesized at room temperature by alternate deposition of titanium and bombardment by nitrogen ions with an energy of 40KeV. The component depth profiles and the structure of titanium nitride films were investigated by means of RBS, AES, TEM, XPS and X-ray diffraction. The results showed that titanium nitride films formed by ion beam enhanced deposition (IBED) had columnar structure and were mainly composed of TiN crystallites with random orientation. The oxygen contamination in titanium nitride films prepared by IBED was less than that of the deposited film without nitrogen ion bombardment. It was confirmed that a significant intermixed layer exists at the interface. The thickness of this layer was about 40 nm for the film prepared on iron plate. The mechanical properties of the film have been investigated. The films formed by IBED exhibited high hardness, improved wear resistance and low friction. INTRODUCTION Titanium nitride film as a coating layer is useful in improving wear and corrosion resistance properties of metals [1] because of its high hardness and good chemical stability. The commonly used methods for preparing such films are still limited in application for reasons, such as high temperature processing, insufficient adhesion of film to substrate etc. The technique of ion beam enhanced deposition (IBED) is one of the newest areas being investigated in respect to modifying surface properties of solids [2-3]. By combining ion implantation with various kinds of deposition, thick, dense and strongly adhesive coating films can be produced. R.A. Kant et al. [4] and B.D. Sartwell [51 have synthesized titanium nitride films by IBED in a chamber backfilled with nitrogen gas. Results showed that the films consisted of TiN crystallites with no preferential grain orientation and the surface was flat and smooth with no indication of porosity. Also the films showed strong adhesion, low friction and wear. The results of M. Kiuchi et al. [61 showed that titanium nitride films formed by IBED had columnar structure with (111) axes preferred orientation. In this paper, we present our work on synthesis of titanium nitride films by alternate Ti-deposition and N+-implantation in a processing chamber of higher vacuum. Results on the composition, structure and mechanical properties of the film will be discussed. EXPERIMENTAL The growth of titanium nitride films was carried out in an Eaton Z-200 Ion Beam Enhanced Deposition System. The system has

MaL Rles. Soc. Symp. Proc. Vol. 128. g1989 Materials Research Society

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been described in a previous paper [7]. The base pressure in the processing chamber was 10-' Torr, and reached a magnitude of 10' Torr during processing. Polished sample substrates were made of 40CrNiMo s