Microwave combustion synthesis of in situ Al2O3 and Al3Zr reinforced aluminum matrix composites

Abstract Al 2 O 3 and Al 3 Zr reinforced aluminum matrix composites were fabricated from Al and ZrO 2 powders by SiC assisted microwave combustion synthesis. The microstructure and reaction pathways were analyzed by using differential scanning calorimetry (DSC), X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and energy dispersive spectroscopy (EDS). The results showed that the heating rate during microwave synthesis was very high and the entire process took several minutes and that the ignition temperature of the reaction was much lower than that of conventional methods. In addition, the resulting microstructure was found to be finer than that prepared by the conventional methods and no cracks can be seen in the Al 3 Zr reinforcements. As such, the newly developed composites have potential for safety-critical applications where catastrophic failure is not tolerated.