Magnesium–samarium oxide nanocomposites: Room-temperature depth-sensing nanoindentation response

Lightweight energy-saving magnesium (Mg) nanocomposites could be titled materials of future. Remarkable specific strength along with acceptable ductility is two key features of these materials which have made them a unique class of emerging materials. However, magnesium nanocomposites are at the initial stages of development and therefore systematic research is required to establish microstructure/property relationships at different potential conditions (i.e. temperatures and strain rates). In this paper, a recently introduced magnesium-samarium oxide (Mg–Sm2O3) nanocomposite, with different volume fractions of nanosize Sm2O3 particles as reinforcement, is employed to study ambient temperature rate-dependent plastic response of the material. To study the rate-dependent response of the materials, a depth-sensing nanoindentation measurement technique was used which is considered a non-destructive, robust, and convenient method to assess the controlling mechanisms of creep phenomenon in small scales. Tests were performed on both nanocomposites and pure Mg for the purpose of comparison. Microstructural observations and nanoindentation data indicate that the creep resistance of the materials is directly associated with the volume fraction of the nanoparticles. The results of this study would provide the required reference lines for the forthcoming elevated temperature creep assessment of the materials.