Microstructure and Corrosion Resistance of Ti-Nb-Ni Amorphous Films on Uranium Surface

Abstract:

Ti-Nb-Ni alloy films were prepared on uranium substrate by unbalanced twin target magnetron sputtering at different bias voltages and deposition rates. The microstructure and corrosion resistance of the films were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and electrochemical polarization experiments. The results show that the Ti-Nb-Ni films are crystal when the deposition rate ratio of Ti:Nb:Ni is 3:1.5:1.5 at 0 V bias voltage. But the Ti-Nb-Ni films are amorphous when the control current of Ti deposition rates is from 5 A to 7 A with unchanged deposition rates of Nb and Ni. The microstructure evolution of the alloy films is as following: amorphous→dispersed small grains→dense small grains→large grains with the bias voltage increasing from 0 to –2000 V. The electrochemical polarization experiments indicate that the films prepared by the compounding techniques of non-crystallization and crystallization have excellent corrosion resistance.

Key words:uranium; Ti-Nb-Ni; amorphous film; microstructure; electrochemical polarization