Corrosion behaviour of low-cost Ti–4.5Al– x V– y Fe alloys in sodium chloride and sulphuric acid solutions

Abstract

The electrochemical behaviour of low-cost α+β Ti–4.5Al–xV–yFe (where x + y = 4; x = 1-3; and y = 1-3) alloys and commercial Ti–6Al–4V alloy was compared in sodium chloride and sulphuric acid solutions. The low-cost alloys were developed by partial substitution of vanadium with iron and the reduction in aluminium content from 6 to 4.5 wt-%. The influence of iron addition and reduction in aluminium content on the corrosion performance of the experimental alloys was assessed via open circuit potential, potentiodynamic polarisation measurements and scanning electron microscopy. The results show that partial replacement of vanadium with up to 3 wt-% iron and the reduction in aluminium content yielded superior corrosion resistance in some of the low-cost alloys when compared with the commercial Ti–6Al–4V alloy. The Ti–4.5Al–1V–3Fe experimental alloy could serve as an alternative low-cost alloy to commercial Ti–6Al–4V alloy in a number of land-based applications such as marine, chemical and petrochemical industries.