Activation energy of self-heating process studied by DSC: Combustion synthesis mixture of Ti-75 at% Al

In order to identify the kinetic process of self-heating in DSC experiment for Ti+3Al→TiAl 3 reaction, two approaches, linear-fitting approach developed from Semenov's theory of spontaneous ignition and variation ofFriedman method, were carried out with cylindrical Ti-75 at% Al samples. Following these approaches, two identical activation energies are obtained as 169±15 kJ mol -1 and 170±5 kJ mol -1 , respectively. Compared with the activation energies of reactions and interdiffusions between Ti and Al, the possible rate-controlling process of self-heating in DSC experiment for Ti+3Al→TiAl 3 reaction is the interdiffusion between Ti and Al through TiAl 3 -layer.