Corrosion Behavior of Al7075, Ti-6Al-4V, and Sn-3.6Ag-1Cu Alloys in 3.0 wt.% Sodium Chloride Solutions Using Potentiodynamic Polarization Measurements

摘要

The corrosion behavior of Al7075, Ti-6Al-4V, and Sn-3.6Ag-1Cu alloys in 3.0 wt.% sodium chloridesolution has been investigated using potentiodynamic polarization measurements. The galvaniccoupling between Al7075 and Ti-6Al-4V alloys using tin-base alloy, copper, and copper coatingsmixed with Sn-3.6Ag-1Cu interlayers at different bonding periods has been also carried out. The effectof bonding time on the galvanic corrosion between Al7075 and Ti-6Al-4V alloys in NaCl solution wasalso reported. It has been found that the corrosion of the individual alloys decreases in the orderAl7075 > 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 galvaniccorrosion through decreasing their corrosion parameters, i.e., corrosion current density (jCorr) andcorrosion rate (RCorr) 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 coppercoating with the combination of Sn-3.6Ag-1Cu interlayer increases the galvanic corrosion byincreasing the values of jCorr and RCorr and decreasing the values of Rp. Therefore, bonding Al7075 toTi-6Al-4V alloys using Sn-3Ag-1Cu thin interlayer was preferred over the copper interlayer andcopper coatings in term of corrosion resistance in the chloride test solution.