Tensile properties of reactive stir-mixed and squeeze cast Al/CuOnp-based metal matrix nanocomposites

Metal matrix nanocomposites (MMNCs) are expected to possess superior mechanical properties that would make them ideal candidates to increase energy and fuel efficiency in the transportation sector. However, economical methods to disperse nanoparticles in metals must be developed to reach this goal. In this work, MMNCs were synthesized from Al and CuOnp by reactive stir mixing followed by squeeze casting. Subsequently, the tensile properties of these materials were measured to determine the effect of the initial nanoparticle (NP) concentration of CuOnp on the exhibited tensile properties. Comparison of the MMNCs processed under the same conditions and tested in the as-cast condition shows an apparent increase in ultimate tensile strength (UTS), but little change in yield strength and ductility. Grain size was found to decrease with increasing CuOnp concentration. The MMNC behavior is compared to Al-Cu alloys in an attempt to shed light on the mechanisms responsible for the change in properties.