REACTION SYNTHESIS PROCESSES - MECHANISMS AND CHARACTERISTICS

Mechanisms of the self-propagating high-temperature synthesis (SHS) are described. The determination of activation energies from wave velocity measurements and temperature profile analyses is discussed. The application of these methods to the respective cases of titanium nitride and zirconium boride is provided. The utilization of the SHS method for the preparation of ceramic-ceramic and ceramic-metallic composites is described with a focus on the mechanism. The concept of "SHS diagrams" is proposed, and its utility is demonstrated with the synthesis of hafnium boride as an example. The influence of the activation energy on the establishment of SHS/non-SHS boundaries in these diagrams is described.