Corrosion Properties of Ultra-Fine-Grained Cu-3 wt%Ti Alloy Fabricated by Combination of Hot Rolling and Aging Treatment.

Although deformation and aging treatments of Cu-3 wt%Ti alloys dramatically enhance their mechanical properties, the corrosion behavior of ultra-fine grained (UFG) Cu-3 wt%Ti alloys produced by a combination of hot rolling and artificial aging has not been extensively explored yet. To bridge this gap, we herein probe the corrosion behavior of an UFG Cu-3 wt%Ti alloy produced by cold rolling and artificial aging, revealing that cast sample corrosion preferentially occurs around the -Cu₄Ti phase. Compared to that of the coarse-grained Cu-3 wt%Ti alloy, the corrosion resistance of its UFG counterpart is remarkably higher, which is ascribed to the effects of grain refinement and enveloping between the -Cu matrix and -Cu₄Ti in the absence of pitting corrosion. The development of ultra-fine microstructure upon the introduction of severe deformation is shown to dramatically improve the corrosion resistance of aging-hardened Cu-3 wt%Ti alloys without sacrificing their mechanical properties. Finally, we demonstrate that solid solution treatment of the Cu-3 wt%Ti alloy results in serious mechanical property deterioration, even though the thus treated samples feature the lowest corrosion current density.