In situ aluminum matrix composites fabricated from Al-Ni2O3 system through microwave synthesis

Aluminum matrix composites reinforced with alpha-Al2O3, Al3Ni2 and Al3Ni2 particulates were fabricated from Al and Ni2O3 powders by microwave synthesis. The reaction processes and resulting microstructures were analyzed by using differential scanning calorimetry, X-ray diffraction, scanning electron microscopy and energy dispersive spectroscopy. The results showed that the ignition temperatures of the reactions generated by microwave and conventional methods were approximately 695 degrees C and 735 degrees C, respectively. The time of microwave heating synthesis was about 8 min, which was much shorter than the time (more than 60 min) consumed by conventional heating method. It was found that the microstructure prepared by microwave heating was finer than that by conventional methods. The densities of the composites fabricated by microwave heating and conventional heating were 2.433 g/cm(3) and 2.622 g/cm(3), respectively. Some intermediate compounds were also observed in the final composites prepared by microwave heating synthesis. (C) 2015 Elsevier B.V. All rights reserved.