In the present study, the mechanical properties of magnesium composites containing nano-ZnO particles are investigated. An increase in microhardness was observed with increasing amount of ZnO from 0·5 to 1·5 vol.- in magnesium. The tensile and compressive yield strengths of the composites remained similar to that of Mg. This is attributed to the heterogeneous grain size distribution and the resultant weak basal texture. The tension–compression yield asymmetry was also found to be minimal due to the lack of strong basal texture. The composites showed improved ultimate tensile and compressive strengths, and this is attributed to well known strengthening mechanisms due to the presence of fine reinforcement particles. The tensile failure strain was significantly improved in composites, while there was a compromise in compressive failure strain. The improved tensile failure strain was due to non-basal slip activation through grain refinement and lack of intense basal intensity in composites.

In this study, magnesium composites with nano-size boron nitride (BN) particulates of varying contents were synthesized using the powder metallurgy (PM) technique incorporating microwave-assisted two-directional sintering followed by hot extrusion. The effect of nano-BN addition on the microstructural and the mechanical behavior of the developed Mg/BN composites were studied in comparison with pure Mg using the structure-property correlation. Microstructural characterization revealed uniform distribution of nano-BN particulates and marginal grain refinement. The coefficient of thermal expansion (CTE) value of the magnesium matrix was improved with the addition of nano-sized BN particulates. The results of XRD studies indicate basal texture weakening with an increase in nano-BN addition. The composites showed improved mechanical properties measured under micro-indentation, tension and compression loading. While the tensile yield strength improvement was marginal, a significant increase in compressive yield strength was observed. This resulted in the reduction of tension-compression yield asymmetry and can be attributed to the weakening of the strong basal texture.