SHS (Self-sustained high-temperature synthesis) of intermetallic compounds: effect of process parameters by computer simulation

Porous Ni–Ti ignition and combustion synthesis

“…Concerning thermal conductivity of pressed powders, it can actually differ from the bulk value because of the porosity [33], and is one of the most relevant parameters in defining the combustion behavior [34]. Thermal conductivity evaluation is here based on the capability to heat the upper side of the sample, by laser energy, and then to measure the temperature evolution in time, by two thermocouples placed at a known distance, inside the pellet [35].…”

Dynamic behavior in self-propagating high-temperature synthesis of intermetallic compounds

“…For a comprehensive account of the computational method, we make here reference to previous works [18][19][20][21][22] on the SHS reaction of solid Zr in O 2 gas to produce the oxide ZrO 2 . For this reaction, the simulations have shown a route to chaos closely resembling the previously referred sequence of bifurcations found by Bayliss and Matkowsky [14][15][16][17].…”

“…For these reasons, the present authors have developed a general purpose numerical method for investigating SHS processes [18][19][20][21][22], The method is based on the uncoupling of macro-kinetics and micro-kinetics, where the former aspect takes care of heat transport as described by Fourier equation, while the latter one models chemical and phase transformations at the level of the grains of the interacting particles, and can involve at will many different reaction steps and different mechanism for each step.…”

Experimental and Numerical Studies on Self-Propagating High-Temperature Synthesis of Ta5Si3 Intermetallics

“…For the Arrhenius factor (K0) of the rate function, Li [17,18] respectively, from elemental powder compacts. On account of the porous nature of the powder compact, Gennari et al [20,21] introduced an effective thermal conductivity (keff) equal to 1/70 of the bulk value (kbulk) to their computation model for the study of the SHS process on the formation of transition metal aluminides. Based upon good agreement between measured and calculated combustion wave velocities and temperatures, Yeh et al [19] further indicated that keff of the Ni-Al powder compacts with relative densities of 50%-65% falls within the extent of keff/kbulk = 0.016-0.052.…”