Nanomechanical properties of magnesium-based hybrid composites with graphite nanofiber and alumina short fiber

Abstract

In this study, an attempt was made to evaluate the nanomechanical properties of magnesium-based hybrid composites with graphite nanofibers (GNFs) and alumina short fibers (Al2O3sf) by nanoindentation. The nanoindentation was performed using continuous stiffness measurement (CSM) method with an indentation depth of 2000 nm. To find out the modulus and hardness of composites of local regions, indentation tests were carried out in different locations of the sample, such as GNFs/Al2O3sf region, Al2O3sf region, GNFs cluster, and Mg matrix. The modulus and hardness values closer to the GNFs/Al2O3sf region are higher than those of the corresponding to the other regions primarily because of a higher constraint to the localized matrix deformation during indentation. Furthermore, the presence of GNFs can act as a barrier for movement of dislocations enhancing the indentation properties. The presence of MgO/Mg17Al12 also can contribute to improve the nanoindentation properties of the present composite system.