Production of Al2O3 reinforced aluminum based composite materials and investigation of their mechanical properties

In this study, aluminum based composite materials containing 5%, 10% and 15% wt Al2O3 were produced by using powder metallurgy technique. Mixing process was conducted in a high-energy attritor for various durations up to 4 hours. Mixed powders were then compacted under 800 MPa pressure to produce standard transverse rupture block specimens with dimension of 6.35x12.70x31.70 mm. Specimens were then sintered at constant temperature of 650 °C for 4 h under argon atmosphere in a tube furnace. The mechanical properties of the composite specimens were determined by measuring the density, hardness and transverse rupture strength values. Microstructures were also investigated by using optical and scanning electron microscopes. The results showed that, more homogenous dispersion of Al2O3 was obtained in Al matrix with increasing the mixing time in attritor. As a result of homogenous dispersion of Al2O3 particles in Al matrix resulted in an increase in mechanical properties of composite samples. Key Words : Aluminum, Al2O3, Composites, High energy attritor, Mechanical Properties