Nanoscale electro negative interface density (NENID) in magnesium alloy nanocomposites: Effect on mechanical properties

Abstract

In metal matrix composites, particle-matrix interfacial reactions are generally undesirable as this leads to poor interface formation where the particle-matrix stress transfer characteristics are inferior. This is of particular concern regarding magnesium alloy nanocomposites for wide ranging weight critical structural applications. In this study, various magnesium alloy nanocomposites containing Al 2O 3, carbon nanotube, TiC, or Si 3N 4 nanoparticle reinforcement were fabricated using solidification processing followed by hot extrusion. Here and for the first time, Nanoscale Electro Negative Interface Density (NENID) quantifies the nanoparticle-alloy matrix interfacial area per unit volume in the magnesium alloy nanocomposite taking into consideration the electronegativity of the nanoparticle reinforcement. We suggest that (1) NENID affects selected mechanical properties in magnesium alloy nanocomposites and (2) there are two joint mechanisms at nanoscale that enable tensile strength and ductility of the alloy nanocomposites to be simultaneously enhanced. We show that NENID indicates the possibility of relatively increased nanoparticle-alloy matrix interfacial reactions occurring while taking into account thermodynamic considerations. © 2012 Springer Science+Business Media B.V.