Abstract:Molybdenum nitride (Mo-N) modified layer on Ti6Al4V alloy was obtained by the plasma surface alloying technique. The bacteria adherence property of the Mo-N modified layer on Ti6Al4V alloy on the oral bacteria Streptococcus Mutans was investigated and compared with that of Ti6Al4V alloy by fluorescence microscopy. The mechanism of the bacteria adherence was discussed. The sample was characterized by X-ray diffractometry (XRD), X-ray photoelectron spectroscopy (XPS) and rough-meter. The results show that the Mo-N modified layer is composed of phase Mo₂N (fcc) and Mo₂N (tetr). There are Mo 3d, N 1s, C 1s and O 1s in the Mo-N modified layer Ti 2p, O 1s, C 1s, in the Ti6Al4V alloy. The surface roughness (R_a) of Ti6Al4V alloy and the Mo-N modified layer is (0.06±0.01) μm and (0.16±0.01) μm, respectively. The Mo-N modified layer inhibits the bacteria adherence. Mo and N on surface of modified layer play a vital role in inhibiting the bacteria adherence.

Key words: Ti6Al4V; Mo-N modified layer; bacteria adherence property