Investigation of Anti-Corrosion Resistance and Morphology of Titanium/Zirconium Conversion Coating on AL-2024 Alloy

In this research, the anti-corrosion resistance of titanium/zirconium based conversion coating on Al-2024 substrate was investigated. Ti/Zr solution practical parameters such as acids concentrations(1, 5, 10 g/lit) solution pH (3, 4, 5), and immersion time (1, 3, 5 min) were optimized Obtained result from DC (Direct polarization) and EIS (Electrochemical Impedance Spectroscopy) revealed that Ti/Zr conversion coating with the acid concentration of 1 g/lit for both H2ZrF6 and H2TiF6 solution pH equal to 4 and immersion time of 3min had the highest anti-corrosion performance. Corrosion current density and low frequency impedance values for untreated substrate are 48.1 μA/cm2 and 1439 ohm.cm2 respectively. These values for optimized Ti/ Zr conversion coating are 6.1 μA/cm2 and 4206 ohm.cm2. Also, field emission scanning electron microscope (FE-SEM) and atomic force microscope (AFM) images indicated the presence of fine and compact particles on the surface of Ti/Zr treated substrate