The morphology and the agglomerate size distribution of the milled powders were studied by field emission scanning Celastrol microscopy (SEM, Hitachi 4160, 15 kV).
3. Results and discussion
3.1. Thermodynamic evaluation
Reaction thermodynamics can contribute to understand the basic information about reactions, and to estimate their behavior and formation of the possible phase compositions during the mechanochemical process . The general form of the reaction taking place in the Mg + TiO2 + C system (stoichiometric ratio) is represented in Eq. (4).equation(4)2Mg+2TiO+C=2MgO+TiC.2Mg+TiO2+C=2MgO+TiC.
This reaction includes two stages: first, reduction of TiO2 by Mg which is a highly exothermic reaction (5) (thermite reaction), and second, the reaction of elemental Ti with C which leads to TiC formation (6) (synthesis reaction).equation(5)TiO2+2Mg=Ti+2MgOΔH0298=−258.45kJmol−1ΔG0298=−249.29kJmol−1equation(6)Ti+C=TiCΔH0298=−184.50kJmol−1ΔG0298=−180.85kJmol−1.