Abstract
The corrosion behavior of Al7075, Ti-6Al-4V, and Sn-3.6Ag-1Cu alloys in 3.0 wt.% sodium chloride solution has been investigated using potentiodynamic polarization measurements. The galvanic coupling between Al7075 and Ti-6Al-4V alloys using tin-base alloy, copper, and copper coatings mixed with Sn-3.6Ag-1Cu interlayers at different bonding periods has been also carried out. The effect of bonding time on the galvanic corrosion between Al7075 and Ti-6Al-4V alloys in NaCl solution was also reported. It has been found that the corrosion of the individual alloys decreases in the order Al7075 > Sn-3.6Ag-1Cu > Ti-6Al-4V. Also, increasing the boding time between Al7075 and Ti-6Al-4V alloys using Sn-3.6Ag-1Cu interlayer from 10 min to 60 min highly decreases their galvanic corrosion through decreasing their corrosion parameters, i.e., corrosion current density (j(Corr)) and corrosion rate (R-Corr) as well as increasing their polarization resistance (Rp). On the other hand, coupling Al7075 and Ti-6Al-4V alloys via bonds made using copper interlayers and further copper coating with the combination of Sn-3.6Ag-1Cu interlayer increases the galvanic corrosion by increasing the values of j(Corr) and R-Corr and decreasing the values of Rp. Therefore, bonding Al7075 to Ti-6Al-4V alloys using Sn-3Ag-1Cu thin interlayer was preferred over the copper interlayer and copper coatings in term of corrosion resistance in the chloride test solution.