A method for determining the kinetics of and the activation energy for the thermal
dissociation of T12AIN and T14AIN3 in vacuum using in-situ time-of-flight (ToF) neutron diffraction
is described. We discuss the thermal stability and phase transitions in Ti2AIN and Ti4AIN3. The 4th
order polynomial function of time [y(t)=At4+Bt3+Ct2+Dt+E] is used to describe the isothermal
decomposition and to calculate the mean value of the reaction rate constant at 1400, 1450, 1500,
and 1550 °C. The rate constants at these four temperatures are used to determine the activation
energy for the decomposition of Ti4AIN3 and Ti2AIN in vacuum using the Arrhenius equation,
which are found to be 410.8 ± 50.0 and 573.8 ± 130 kj/mol, respectively.