Reaction synthesis of (Ti,Cr)2AlC/Al2O3 in situ solid solution composite

The (Ti,Cr)(2)AlC/Al2O3 solid solution composite has been synthesized by in situ aluminothermic reduction of the blend powders of Ti, Al, Cr2O3 and carbon black. The phase evolution during the formation of the composite was examined at the temperatures from 700 degrees C to 1400 degrees C. Based on the results of X-ray diffractometry (XRD) and differential scanning calorimeter (DSC), a possible reaction mechanism was brought forward to explain the formation of (Ti,Cr)(2)AlC/Al2O3 solid solution composite. Above the melting point of aluminum, liquid Al reacted with titanium to form the intermetallic compound of TiAl. As the temperature increased to 900 degrees C, the intermetallic compound of TiAl reacted with TiC to form Ti2AlC. The microstructures of the as prepared samples were also analyzed by the scanning electron microscope (SEM) together with the election dispersive spectroscopy (EDS).