PHYSICAL, STRUCTURAL AND MECHANICAL CHARACTERIZATION OF TI1-XSIXNY FILMS

Within the frame of this work, Ti1-xSixNy hard coatings with 0 less th an or equal to x less than or equal to 0.37 and thicknesses ranging fr om 1.2 to 3.5 mu m, were prepared by r.f. reactive magnetron sputterin g in an Ar/N-2 gas mixture. X-ray diffraction and Fourier analysis of X-ray profiles were used to investigate the structure and grain size, and its correlation with hardness behaviour, as a function of the Si c ontent, bias voltage and working gas (argon) flow rate. In this respec t, the results show that a double cubic phase of NaCl type was develop ed with lattice parameters of 4.18 and 4.30 Angstrom, revealing the (1 11) orientation for low Si content (x=0.05), (220) for intermediate Si contents (0.13 less than or equal to x less than or equal to 0.22) an d (200) for the highest Si contents (0.30 less than or equal to x less than or equal to 0.37). Regarding the results of ultramicrohardness t ests, and although all samples with 0.05 less than or equal to x less than or equal to 0.30 present a hardness value higher than 30 GPa, the Ti0.85Si0.15N1.03 revealed the highest hardness value, around 47 GPa, which is more than twice as high as that of common TiN. Furthermore, the study of hardness as a function of the applied bias voltage reveal ed that best results are achieved between -50 and 0 V. The variation i n hardness as a function of the argon flow showed that best results in hardness are obtained when working with flow rates around 110 cm(3)/m in. (C) 1998 Elsevier Science S.A. All rights reserved.