A New Expression for Velocity of the Combustion Front during Self-Propagating High-Temperature Synthesis

Abstract

The method of self-propagating high-temperature synthesis (SHS) can be utilized to produce a variety of advanced materials. After ignition, due to high exothermicity of the reactions involved, the process is characterized by a combustion wave which propagates through the reacting mixture in a self-sustained manner without requiring additional heat. By assuming that the reaction rate is proportional to the instantaneous surface area of the nonmelting component and to the instantaneous concentration of the melting reactant in the formed outlying melt, a new analytical expression for the velocity of the combustion front is developed. This expression accounts for the influence of temperature, particle size, reactant proportions and inert dilution. Experimental data for front propagation velocity for the titanium-carbon reaction available in the literature are described with good accuracy by the expression developed in this work.

Key Words:

• Self-propagating high-temperature synthesis
• Wave velocity
• materials synthesis
• melting reactant
• diffusional limitations

Additional information

Notes on contributors

ARVIND VARMA

Author to whom correspondence should be addressed.