The varied kinetics mechanisms in the synthesis of MgB2 from elemental powders by low-temperature sintering

▶ The reaction between Mg and B during the low-temperature sintering is controlled by varied mechanisms. ▶ At initial stage, the reaction rate is mainly controlled by phase boundary reaction mechanism. ▶ As the reaction prolongs, the diffusion-limited mechanism gradually becomes dominant. ▶ The corresponding activation energy is also decreased firstly and then increased again during the whole reaction process.