SURFACE PROPERTIES OF TITANIUM ALLOY VT 6 AFTER PLASMA ELECTROLYTIC TREATMENT

Surface modification of titanium alloy VT 6 in aqueous solution containing 5 wt% of ammonium hydrate and 10 wt% of ammonium chloride in a temperature range of 650- 900 ºC by plasma electrolitic treatment was carried out. Characterization of surface layers of the alloy after plasma electrolytic treatment was done by Fourier Transform Infrared spectroscopy (FTIR) and powder X-ray diffraction (XRD). The FTIR spectra were recorded on a spectrometer BrukerVertex80 at room temperature in the range of 7500-350 cm-1. The spectra show the presence of rutile phase on the alloy surface after the plasma electrolytic treatment in the electrolyte solution of the indicated composition. The intensive bands at 654-643 cm-1, the weak bands near 560 cm-1 and the bands at 425-416 cm-1 can be assigned to rutile. The bands at 466-462 cm-1 are related to Ti-O-Ti stretching vibrations. With increasing temperature the relative intensity of the bands assigned to rutile increase. The plasma electrolytic treatment leads to appearence of the bands testifying enrichment of the alloy surface by nitrogen: the bands at 1634-1622 см-1 can be assigned to asymmetric bending of NH4+; the bands about 1539 cm-1 are related to N-H bending or symmetric bending of NH4+. The bands about 1428-1426 cm-1 can be also assigned to NH4+ bending vibrations. The plasma electrolytic treatment in the temperature range of 650-750 ºС results in appearance of the bands at 1069-1064 см-1. According to literature data, the bands can be assigned to vibrations of Ti-O-N. X-ray diffraction analysis allowed to ascertain crystal structure, phase identification of the titanium alloy VT 6 after its plasma electrolytic treatment. The measurements were performed using a Bruker D8 Advance diffractometer with Mo Kα radiation (λ=0.07107 nm). Analysis of XRD patterns showed that titanium oxide in the samples is present as hongquiite phase (γ- monoclinic singony) and magnesium phase (hexagonal singony). Besides the peaks of TiO, the peaks which are characteristic for hamrabevit TiC in halite phase (cubic syngony) and Ti2O3 in corundum phase (trigonal syngony) were observed.Forcitation:Parfenyuk V.I., Tesakova M.V., Lutovac M., Kusmanov S.A., Lutovac B., Belkin P.N., Parfenyuk E.V. Surface properties of titanium alloy VT 6 after plasma electrolytic treatment. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2018. V. 61. N 3. P. 58-63