Structural and mechanical characterization of stir cast Al–Al 2 O 3 –TiO 2 hybrid metal matrix composites

The present paper reports the effect of aluminium oxide and titanium oxide reinforcement on the properties of aluminium matrix. Aluminium matrix reinforced with aluminium oxide–titanium oxide (2.5, 5.0, 7.5 and 10 wt.%) in equal proportion were prepared by stir casting. Phase, microstructure, energy dispersive spectroscopy, density, hardness, impact strength and tensile strength of prepared samples have been investigated. X-ray diffraction reports the intermediate phase formation between the matrix and reinforcement phases due to interfacial bonding between them. Scanning electron microscopy shows that aluminium matrix has uniform distribution of reinforcement particle i.e. aluminium oxide and titanium oxide. Density of composite decreases due to variation of reinforcement and it shows low density after preheating. Hardness decreases due to the amalgamation of reinforcements. Impact strength was found to increase with the addition of reinforcements. Hybrid composite of aluminium matrix and (5% aluminium oxide + 5% titanium oxide) reinforcements have maximum engineering and true ultimate tensile strength. It is expected that the present hybrid metal matrix composites will be useful for aircraft rivets.