TRIBOLOGICAL BEHAVIOR OF TIN, TICXNY AND TIC COATINGS PREPARED BY UNBALANCED MAGNETRON SPUTTERING TECHNIQUES

TiN, TiC and TiCxNy (0<x<1, 0<y<1) coatings were deposited onto AISI 4 20 substrates by unbalanced magnetron sputtering techniques at the sub strate temperature of 350-degrees-C. The structures of all the coating s were examined by X-ray diffraction and Rutherford backscattering spe ctrometry. TiN and TiCxNy coatings exhibit a strong (111) or (200) pre ferred orientation. TiC coating exhibits a (220) preferred orientation . The hardness values for all the coatings increase with the carbon co ntent varying between pure TiN and pure TiC coating. The different tri bological behavior of TiN, TiC and TiCxNy coatings were investigated a nd compared. The amount of surface wear was evaluated by optical and s canning electron microscopy. The results of the wear tests show that f riction coefficients are in the range 0.17-0.3 for all coatings. The w ear lifetimes of the TiCxNy coatings with different carbon concentrati ons increase with the carbon content from 11 to 32 h. Relative soft Ti N coatings exhibit a short wear lifetime, about 3.5 h. In general, the wear behaviors of TiCxNy coatings with high carbon content are superi or to those of either TiN or TiC coating.