Synthesis and formation mechanism of high-purity Ti3AlC2 powders by microwave sintering

High-purity titanium aluminum carbide (Ti 3 AlC 2 ) powders were synthesized by a microwave sintering method using different titanium sources as raw materials. The prepared products were characterized by differential scanning calorimetry (DSC), X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The results indicated that the synthesized Ti 3 AlC 2 powders have high purity (97.5%) and even distribution of the grain size when using a 3TiH 2 /1.2Al/2C mixture as raw materials when the microwave sintering temperature and time were 1300°C and 30 minutes, respectively. The formation mechanism of the Ti 3 AlC 2 is described as proceeding via four stages. The solid-phase reaction between titanium and aluminum occurs below the melting point of aluminum and the main product is a Ti 3 Al phase, which is an observed intermediate compound for the formation of Ti 2 AlC and Ti 3 AlC 2 . Thus, this study provides a beneficial approach to low-temperature synthesis of high-purity Ti 3 AlC 2 materials.