STUDY OF THE COMPOSITION AND OF THE MECHANICAL-PROPERTIES OF TIBN FILMS OBTAINED BY DC-MAGNETRON SPUTTERING

The growth of Ti-B-N films obtained by d.c. magnetron cathodic sputter ing is studied. The wide influence of process parameters such as nitro gen flow rate, bias voltage and growth temperature on composition and on mechanical properties such as hardness, wear resistance, adhesion a nd intrinsic stress is pointed out, When nitrogen is introduced (even at a low flow rate) the films appear to be amorphous by XRD analysis. The XPS analysis shows the presence of Ti-B, Ti-N and B-N bondings who se proportions depend on the nitrogen flow rate. The mechanical proper ties are a function of the relative amounts of these bondings. The hig hest microhardness (approximately 40 GPa) is obtained when the proport ions of Ti-B, Ti-N and B-N bondings are comparable. This high hardness value leads to a good wear resistance which is associated to a low co mpressive stress level (between -1 and -2 GPa).