Electrochemical characteristics of titanium alloy in engine oil and NaCl solution

The electrochemical characteristics of a titanium alloy Ti-6Al-1.5Cr-2Zr in 3# kerosene and 928 lubricating oil with high resistance were studied by using potentiodynamic polarization. The electrochemical properties including the laws of polarization, open-circuit potential, linear polarization resistance and variation of corrosion current were investigated. The corrosion behaviors of titanium alloy were investigated by using immersion method in 3 kerosene and 928 lubricating oil. No visible corrosion appeared in the oil medium. The electrochemical characteristics of the alloy in 3.5% NaCl solution were also studied to compare that in the oil medium. The open-circuit potential is -0.18 V, passivation potential is 0.23 V, passivation current density is 0.31×10 A/cm² in 3.5% NaCl solution and the passivation area potential is in the range of 0.27-1.24 V in 3.5% NaCl solution.