Interface precipitation and corrosion mechanisms in a model Al–Zn–Mg–Cu alloy strengthened by TiC particles

Abstract

Interface precipitation and corrosion behaviors in the cast and extruded TiCp/7050 composites are comprehensively investigated herein. Aging precipitates are inclined to segregate at α-Al/TiC interfaces and preferential dissolution of interface precipitates aggravates localized corrosion susceptibility of composites. Moreover, distribution configurations of TiC affect corrosion resistance of composites, being composites with dispersively distributed TiC have better corrosion resistance compared to those in which the particles are distributed forming networks or chains. This work discloses the relationship between interfacial precipitation and corrosion mechanisms in the composites, which should shed light on designing and fabricating 7xxx composites with high mechanical and corrosion performance.