Enhanced Corrosion Resistance in an Additively Manufactured Copper Alloy via Suppressed Segregation

ABSTRACT

This study elucidates the corrosion behavior of C18150 Cu–Cr–Zr alloy fabricated by laser powder bed fusion (LPBF) in comparison with a conventional wrought baseline representative of industrial Cu–Cr–Zr plate products, highlighting the superior corrosion resistance of the additively manufactured condition. Dense LPBF‐fabricated C18150 specimens were systematically evaluated alongside rolled counterparts using electrochemical measurements, microstructural analyses, and surface characterizations. The as‐fabricated LPBF alloy exhibited a corrosion current density lower than that of the rolled material, which was associated with the LPBF‐induced nonequilibrium microstructure, characterized by a relatively homogeneous Cu–Cr solid solution, suppressed segregation, and moderate dislocation density. This microstructural state mitigated the formation of detrimental micro‐galvanic couples. In contrast, heat treatment of LPBF specimens induced Cr precipitation and increased susceptibility to pitting corrosion. In the rolled alloy, the combination of high dislocation density and pronounced Cr segregation led to Cr‐depleted zones and strong micro‐galvanic cells, ultimately resulting in delamination‐like corrosion. These findings identified the as‐fabricated LPBF state as an optimal condition for corrosion‐critical applications and underscored the potential of microstructure‐guided additive manufacturing to tune the conventional hardness‐corrosion trade‐off in advanced copper alloys.