Application of the Method of Dynamic Diffractometry Using Synchrotron Radiation to Study Phase Formation Processes during the Synthesis of a Mechanically Activated Ti–Al–C Mixture

Using the method of dynamic diffractometry with the use of synchrotron radiation beams, experimental studies of phase formation processes occurring during the high-temperature synthesis of mechanically activated powder mixture Ti + Al + C were conducted. High-temperature synthesis has been carried out in situ in thermal explosion mode using a microwave induction heater on an experimental complex adapted to the method of dynamic diffractometry. The experiments were conducted at the “Diffraction Cinema” station of VEPP-3, channel 5B, at the Budker Institute of Nuclear Physics, Siberian Branch, Russian Academy of Sciences. It has been experimentally shown that the synthesis of a composite material occurs in multiple stages. The onset of phase changes begins at a temperature of approximately 870°C. Initially, the formation of intermetallic compound TiAl3 is observed. Then a Ti–Al melt is formed with the release of TiC grains, which provides the main heat release and initiates a thermal explosion reaction. Further, the Ti–Al melt due to the dissolution of TiC grains in it is saturated with carbon, and when the temperature reaches 1800°C, MAX phase Ti2AlC crystallizes from it. The maximum amount of this phase is fixed at the exposure stage. With a decrease in temperature, along with Ti2AlC, MAX phase Ti3AlC2 is formed. At this stage, by controlling the temperature, it is possible to control the content of MAX phases in the reaction product. The composition of the final product includes Ti3AlC2, Ti2AlC, and TiC.