Fabrication of Ti–Al–Cu new alloys by inductive sintering, characterization, and corrosion evaluation

Abstract

The current work reports the manufacturing and electrochemical characterization of Ti–5%Al–5%Cu, Ti–5%Al–10%Cu, and Ti–5%Al–20%Cu alloys, which were fabricated using mechanical alloying technique. The corrosion of these alloys after varied immersion periods of time in 3.5% NaCl solution was studied using electrochemical impedance spectroscopy (EIS), potentiodynamic polarization, and potentiostatic current time measurements. The phase analyses of the alloys were investigated using X-ray diffraction. Scanning electron microscopy (SEM) was employed to observe the surface morphology of the corroded surfaces whereas the composition of the corrosion products formed on the alloys surfaces was examined using energy dispersive X-ray spectroscopy (EDX). The uniform corrosion of these alloys was found to greatly decrease with the increase of Cu content from 5 wt% to 20 wt%, this occurrence is due to decreasing the values of corrosion current (jCorr) together with corrosion rate (RCorr) and increasing the corrosion resistance (RP). Prolonging the immersion time up to 48 h was found to further increase the values of RP and decrease the values of jCorr and RCorr. Both the electrochemical and the spectroscopic investigations indicated that the increase of Cu content and prolonging the immersion time have significantly decreased all corrosion parameters and increase the corrosion resistance of the alloys in NaCl solution. Keywords: Ti-base alloys, Corrosion, Mechanical alloying, Electrochemical techniques