Microstructural and mechanical properties of Al2O3 reinforced Al7010 matrix composites, fabricated by stir casting

Abstract

The microstructural and mechanical properties of alumina reinforced Al7010 matrix composites, fabricated by stir casting, were investigated by varying size and volume fractions of alumina particles. The optical microscope, micro Vickers hardness tester, tensile tester, and impact testers were used to evaluate the microstructure and mechanical properties of produced alumina reinforced Al7010 matrix composites. Results show that the alumina reinforced Al7010 matrix composites, incorporating lower volume fractions of alumina particles, exhibited much better morphological and mechanical properties than composites with higher volume fractions. The composite with 14% alumina particles of size 15 µm exhibited uniform dispersion of alumina particles in the Al7010 matrix with superior interfacial bonding and negligible agglomeration of alumina particles and excellent morphological properties. On the other hand, the composite, having 21% alumina particles of size 1 µm demonstrated very poor morphological properties and intensive agglomeration of alumina particles. Similarly, the maximum values of Rm (349 MPa) and ƐT (3.41%) were also offered by composite, incorporating 14% Al2O3 particles of size 15 µm attributed to the uniform dispersion and negligible agglomeration of alumina particles throughout the matrix. The composite with 21% alumina particles of size 1 µm offered the minimum values of Rm (172 MPa) and ƐT (1.69%) due to the presence of intensive agglomeration of alumina particles. The superior impact toughness (11.4 J) and the overall optimum combination of morphological and mechanical properties were offered by the composite with 14% alumina particles of size 15 µm.