Microstructure, mechanical properties, aging behavior, and corrosion resistance of a laser powder bed fusion fabricated Al–Zn–Mg–Cu–Ta alloy

Abstract

An Al–Zn–Mg–Cu–Ta alloy was successfully fabricated by laser powder bed fusion (LPBF). The effect of the added Ta on the microstructures (cracks, grain sizes, and phase constitutions), mechanical properties (tensile strength and elongation), aging behavior, and corrosion resistances (full immersion and electrochemical corrosion performances) of the LPBF-fabricated Al–Zn–Mg–Cu alloy were investigated. The results exhibited that, Ta restrained hot tearing, refined microstructures, enhanced the tensile strength and ductility, accelerated the aging processing, and improved the corrosion resistance of the LPBF-fabricated Al–Zn–Mg–Cu alloy, significantly. The reason was that Ta not only reacted with Al to form in-situ Al3Ta to refine α(Al), but also dissolved in the second phases to inhibit their coarsening.