Modeling of exothermic solid-solid noncatalytic reactions

Abstract

A certain class of refractory materials can be synthesized in the sintering or in the self-propagating regime by a direct reaction between the metal powder and carbon, boron, or silicon. A detailed analysis and modeling of such processes are given. Criteria are derived for stable, unstable, and degenerated combustion as well as approximate relations for the velocity of a constant-pattern profile, as a function of the heat-transfer coefficient. The approximate formulas are verified by a detailed numerical study. Different types of combustion (constant-pattern profiles, standing waves, and complex oscillatory behavior) have been observed.

Fluoroelastomer pyrotechnic time delay compositions

“…Theoretical models for the self-propagating layer-to-layer reactions in the solid phase have been developed [6][7][8][9][10][11][12][13]. They link the rate of progression of the reaction zone through the mixture of the reactants in the form of a cylinder, with the chemical composition and some of the physical properties of the powders, the state of subdivision of the powders, and the reaction kinetics between the constituents [6].…”

Historical perspective and contribution of US researchers into the field of self-propagating high-temperature synthesis (SHS)/combustion synthesis (CS): Personal reflections

“…Professor Hlavacek established a very active research group which focused its research on both experimental studies and mathematical modeling of self-sustaining reactions and materials engineering aspects of combustion synthesis. Due to the access to parallel computer processors in mid 1985, his research modeling team was able to simulate complex combustion patterns, including transition to chaos, breaking of symmetry, fingering effects, multiple spinning waves in two and three dimensions, as well as complex behavior of the combustion front during gassolid reactions [64][65][66][67][68][69][70][71][72][73][74][75][76]. Figure 2 shows the transition to chaos via period doubling in gasless reacting systems.…”

Modeling Reaction Front Propagation and Porosity in Pressure-Assisted Combustion Synthesis of Porous NiTi Intermetallics

“…An increase in enthalpy leads to melting at constant temperature (T 7-8 = 1939 K, Ti b fi Ti l ) h 8 Ti is completely liquid. An increase in enthalpy leads to an increase in the temperature of the mixture Once the transition enthalpies are known, the subroutine employed by the PACS model determines which region the known local enthalpy falls into.…”