An investigation of the relationship between heat treatment and microstructure in (TiAlV)N and (TiAl)N ceramic films Y. Totik*, I ˙ . Efeog ˘lu, M. Gavgali, R. Sadeler Department of Mechanical, Faculty of Engineering, Atatu ¨rk University, Erzurum, Turkey Received 1 December 2000; accepted 1 May 2001 Abstract (TiAl)N and (TiAlV)N films coated on M2 high-speed tool steel were heat-treated in an argon atmosphere at temperatures of 700°C, 800°C and 900°C for 3 h. The structural and mechanical properties of the ceramic films were examined by microindentation hardness testing, X-ray diffraction (XRD) and scanning electron microscopy. Annealing at elevated temperatures led to a decrease in the hardness of the ceramic films. The magnitude of this hardness change became larger with increasing annealing temperature. Elevated temperature anneals also modified the distribution of elements in the ceramic films. XRD data show that phase transformations take place in the structure. These transformations resulted in a decrease in the hardness, residual stress and spacing between the planes of the film. The surface topography was not affected by the heat treatment. D 2001 Elsevier Science Inc. All rights reserved. 1. Introduction Ceramic films produced by physical vapor depos- ition (PVD) and chemical vapor deposition (CVD) techniques have been widely used in mechanical and tribological applications to solve surface engineering problems. Because the hardness, wear resistance, fatigue and corrosion resistance of the ceramic films are considerably higher than those of other materials, ceramic films are widely used as a method of surface modification of engineering materials [1]. In order to improve the features of TiN-based films, deposited compounds such as (TiAl)N, (TiZr)N, (TiAlV)N and (TiAlZr)N have found many applications in recent years. (TiAl)N and (TiAlV)N films have better mech- anical and tribological properties than TiN films [2,3]. One application for ceramic films is to increase the life and decrease the cost of cutting tools [4]. The use of ceramic films requires good adhesion between the substrate and the deposit. The quality of the coating depends on the degree of diffusion between the film and the substrate. When adhesion is weak, the probability of film/substrate separation is high. The relationship between heat treatment and structural and mechanical characteristics of (TiAlV)N and (TiAl)N ceramic films deposited on M2 tool steel by a closed field unbalanced magnetron sputtering (CFUBMS) technique was studied and is reported in this paper. 2. Experimental methods 2.1. Sample preparation and heat treatment (TiAlV)N and (TiAl)N ceramic films were depos- ited on M2 high-speed tool steel by a CFUBMS technique. The thickness of (TiAlV)N and (TiAl)N 1044-5803/01/$ – see front matter D 2001 Elsevier Science Inc. All rights reserved. PII:S1044-5803(01)00152-8 * Corresponding author. Fax: +90-442-2336961. E-mail address: totik@lycos.com (Y. Totik). Materials Characterization 47 (2001) 55 – 60