Self-propagating high-temperature synthesis flammable range and dominant parameters for synthesizing several ceramics and intermetallic compounds under heat-loss condition

Extensive comparisons have been conducted between experimental and theoretical results for the nonadiabatic self-propagating high-temperature synthesis combustion characteristics of many solid-solid systems subjected to volumetric heat loss. The nonadiabatic flame propagation theory-which describes the premixed mode of bulk flame propagation supported by the nonpremixed reaction of dispersed nonmetal (or higher-melting-point metal) particles in the liquid metal, with finite-rate reaction at the particle surface and temperature-sensitive Arrhenius-type condensed-phase mass diffusivity - is used to compare with experimental results with heat loss. Systems examined are ceramics (TiC, TiB₂, and ZrB₂) and intermetallic compounds (NiAl, TiCo, and TiNi). By using a consistent set of physicochemical parameters for these systems, satisfactory quantitative agreement is demonstrated for the flammable range (defined in terms of the mixture ratio, degree of dilution, particle size, and/or compact diameter).