Simultaneously enhanced tensile and compressive response of AZ31–NanoAl2O3–AA5052 macrocomposite

Abstract

New bimetal AZ31–Al2O3/AA5052 macrocomposite comprising (a) Al2O3 nanoparticle-reinforced magnesium alloy AZ31 shell and (b) aluminum alloy AA5052 millimeter-scale core reinforcement was fabricated using solidification processing followed by hot coextrusion. Microstructural characterization revealed more rounded intermetallic particle of decreased size, reasonable Al2O3 nanoparticle distribution, and non-dominant (0 0 0 2) texture in the longitudinal and transverse directions in the AZ31–Al2O3 nanocomposite shell. Interdiffusion of Mg and Al across the core–shell macrointerface into each other was also significant. Compared to monolithic AZ31, the AZ31–Al2O3 shell exhibited significantly higher hardness (+33%). In tension, the presence of Al2O3 nanoparticles (in the AZ31 shell) and AA5052 core significantly increased stiffness (+39%), yield strength (0.2% TYS) (+9%), ultimate strength (UTS) (+19%), average failure strain (+7%), and work of fracture (WOF) (+27%) of AZ31. In compression, the presence of Al2O3 nanoparticles (in the AZ31 shell) and AA5052 core significantly increased yield strength (0.2% CYS) (+58%), ultimate strength (UCS) (+4%), average failure strain (+11%), and WOF (+49%) of AZ31. The effect of joint presence of (a) Al2O3 nanoparticles (in the AZ31 shell) and (b) AA5052 millimeter-scale core on tensile and compressive properties of AZ31 is investigated in this article.