Active-passive behaviour of titanium and titanium alloy (VT-9) in sulphuric acid solution

Abstract

Corrosion behaviour of titanium and VT-9 has been studied in sulphuric acid solution in the whole range of concentration at 30 °C. Effect of temperature on the corrosion behaviour has also been investigated. Titanium and its alloy (VT-9) showed active-passive behaviour. A large range of potential for passivity was observed in all the concentrations at different temperatures. Critical current density for passivation (icr) increased with increasing temperature while it increased with concentration up to 11 M; thereafter it decreased. In general, Ti and VT-9 exhibited similar corrosion behaviour, however passivation current density (ip) and critical current density (icr) differed to some extent. The passivation current density is higher in case of VT-9 than Ti while icr is lower under similar conditions. The stability of the film formed on the surface of the titanium and VT-9, examined under different experimental conditions, reveals the formation of protective uniform passive film on the metal and alloy. © 1993.