Simultaneous Improvement of the Mechanical and Corrosion Properties of a 3102 Aluminum Alloy via Ti Addition

The present study investigates the effects of titanium (Ti) addition on the microstructure, mechanical properties, and corrosion resistance of a 3102 aluminum alloy (Al-0.4Mn-0.3Fe-0.05Si, wt.%; the modified alloy is denoted as 3102-Mod aluminum alloy) through electron backscatter diffraction, x-ray photoelectron spectroscopy, and electrochemical tests. Results demonstrate that the introduction of 0.2-wt.% Ti led to considerable grain refinement, reducing the average grain size from 42 to 19 μm and improving the overall mechanical properties of the 3102 alloy. Notably, the corrosion resistance of the alloy was remarkably enhanced. In particular, the corrosion current density and corrosion rate of the 3102-Mod alloy were lower than those of the 3102 alloy. Furthermore, a Nyquist plot revealed a higher corrosion resistance of the 3102-Mod alloy. This improvement in corrosion resistance can be primarily attributed to the formation of a considerably compact passivation film owing to Ti microalloying. Overall, the findings indicate that Ti microalloying is a new strategy for enhancing the corrosion resistance of 3xxx aluminum alloys, thus expanding their application scope in automotive heat exchangers.