Resumo

ROCHA, R. C. S. et al. Tribological properties modification of titanium by plasma carbonitriding. Matéria (Rio J.) [online]. 2011, vol.16, n.3, pp. 768-774. ISSN 1517-7076.  http://dx.doi.org/10.1590/S1517-70762011000300004.

TiCxNy surfaces were produced by thermochemical treatment achieved by N₂ - Ar - CH₄ plasma mixture. The influence of methane concentration and C and N atoms inserted into the crystalline lattice of Ti were investigated through the characterization of its tribomechanical properties. Therefore, commercially pure Ti (grade II) samples were carbonitrided in the x N₂ - y Ar - z CH₄ plasma mixture (where x and y = 4 SCCM and z = 2, 3 and 4 SCCM) at 500 °C, during 1 h. C and N concentration profile after treatments were determinate by NRA. The superficial phases were identified by GIXRD. Pin-on-disk assays were utilized to determine the friction coefficient, whose damaged areas were studied by perfilometry and scanning electron microscopy (SEM) techniques. It was observed that the friction coefficient and the damage mechanism of Ti are intensively dependent of C and N concentration on the surface. However, the concentration profile of those interstitial elements is not directly proportional to the methane gas flow.

Palavras-chave : plasma; titanium; carbonitriding; tribology.