Features of synthesis and structure formation in the Ti ₃ SiC ₂ MAX phase

This study investigates the synthesis of the MAX phase Ti 3 SiC 2 using pressureless sintering of Ti-Si-C powder mixtures. The influence of sintering temperature on phase formation and microstructure was systematically analysed through differential thermal analysis (DTA), X-ray diffraction (XRD), scanning electron microscopy (SEM), and nuclear magnetic resonance (NMR) spectroscopy. DTA shows the complex phase transformations in the range 1300–1400 °C. XRD analysis showed that the MAX phase content increased with temperature, reaching 94 wt.% at 1395 °C, with minimal content of secondary phases. SEM confirmed that a clearly defined layered microstructure characteristic of the MAX phase is formed. NMR spectroscopy provided insights into the local atomic environment of titanium, revealing two distinct titanium sites with quadrupole coupling constants of 9.3 MHz and 1.7 MHz for ‘outer’ and ‘inner’ titanium atoms, respectively. These findings demonstrate that sintering temperature critically affects the phase yield but not the intrinsic structural characteristics of Ti 3 SiC 2 .