Structural and Phase Stability in the 2TiC-Al-Ti System During Milling and Subsequent Annealing

The aim of the present research was to examine the structural and phase transformations, as well as the phase stability, in the 2TiC-Al-Ti system. A specific ratio of TiC, Al, and Ti powder mixture, based on the stoichiometric reaction for the formation of the Ti3AlC2 compound, was prepared and subjected to milling and annealing processes. The prepared samples were analyzed using scanning electron microscopy (SEM), X-ray diffraction (XRD), and differential scanning calorimetry (DSC). The results showed that milling the 2TiC-Al-Ti powder mixture did not result in the formation of a single-phase Ti3AlC2. Instead, the final structure consisted of a combination of TiC and Ti3AlC2 phases. The Ti3AlC2 phase formed during the milling process was unstable and transformed into a single-phase TiCx structure upon further milling or annealing. Additionally, the effect of the partial addition of Sn and Si on the structural and phase changes in the 2TiC-Al-Ti system during the milling and annealing processes was investigated. It was found that the addition of these elements had little effect on the formation and stability of the Ti3AlC2 compound.