Mechanical Characterization of AA7068-ZrO2 reinforced Metal Matrix Composites

Metal Matrix Composites are significantly contributing towards important role in engineering applications and are in the forefront of significant research in present day due to their scientific and technical advantages. Particle or discontinuously reinforced MMCs are relatively inexpensive and are found to possess specific properties compared to fiber reinforced MMCs. Among the various types of particulate reinforcements such as silicon nitride, boron nitride, silicon carbide, titanium carbide, boron carbide and alumina, extensive research has been directed toward the development of zircon particle reinforcement. Zircon reinforced composites are preferred as these composites exhibit relatively high refractoriness, excellent resistance to abrasion, thermal shock and chemical attack compared to composites reinforced with other reinforcements. The present paper aims the investigation on influence of reinforced particles ZrO2 on mechanical properties of aluminum alloy (AA7068) composites which is developed by stir casting technique. The castings produced were machined and samples were fabricated by varying weight percentage of the reinforced particles as 0, 2, 4, 6, and 8 Wt% in volume. SEM and microstructural studies were carried out on all composites and fractured surface of tensile specimens. Microstructural study reveals uniform distribution of reinforcement ZrO2 particles in as cast and AA7068 metal matrix composites. Significant improvement in Hardness and Tensile strength was found with increase in Zirconium di oxide particles in weight percentage of composites. As expected, the percentage elongation diminished with increased weight percentage of reinforcement in the aluminum matrix. (C) 2017 Elsevier Ltd. All rights reserved.