Nanoindentation characterization of Al-matrix nanocomposites produced via spark plasma sintering

Spark plasma sintering has been recognized in the recent past as a very useful tool capable of producing materials with high strength and low porosity when compared to the traditional powder metallurgy technologies. In addition, the possibility of producing metal-matrix composites with enhanced mechanical and wear properties has been demonstrated. Obviously, the final properties of spark plasma sintered composites depend on the reinforcement type, size and percentage. The present paper analyzes the possibility of producing spark plasma sintered aluminum-based composites with various types and sizes of reinforcement (Al2O3 nanosized and microsized particles blended with aluminum in different percentages). A strong variation in the microstructural behavior, in mechanical properties and in deformation mode has been observed by varying the type, percentage and combination of reinforcements in the aluminum matrix. The material evolution was deeply analyzed through nanoindentation, X-ray diffraction and scanning electron microscopy.