Main Recent Contributions to SHS from France

International audienceBoth in situ TRXRD and IR thermography, on the one hand, and different levels of modeling, on the other, have generated a strong progress in the knowledge and control of numerous SHS reactions. The SHS of simple binary materials, such as intermetallics (FeAl, MoSi2, NbAl3, etc.), oxides (e.g. ZrO2), carbides (e.g. SiC) or nitrides, more complex materials, such as mullite, SiAlONs, MAX phases, composites (SiO2-Al2O3, NiAl-ZrO2 ), powders in their more complicated states, such as well controlled microstructures, fully densified intermetallics, smart composites, and hard coatings carried out by GFA researchers greatly contributed to the worldwide competition to harness the potential of SHS. On the occasion of the 40th anniversary of SHS, this paper is giving an overview of the main results obtained by GFA over the last ten years

Stochastic analysis of limit cycle behavior in spatially extended systems

The statistical properties of a one-dimensional reaction-diffusion system undergoing a Hopf bifurcation are studied using the master equation approach. The analysis reveals nontrivial interferences between macroscopic dynamics and mesoscopic local fluctuations that eventually wipe out any trace of homogeneous oscillations, even though the latter are asymptotically stable solutions of the deterministic equations.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Topics in nonequilibrium statistical mechanics of reactive systems

Doctorat en Sciencesinfo:eu-repo/semantics/nonPublishe

Topics in nonequilibrium statistical mechanics of reactive systems

Doctorat en Sciencesinfo:eu-repo/semantics/nonPublishe

Fluctuations de non-équilibre: propriétés asymptotiques et phénomènes dépendant du temps

Doctorat en Sciencesinfo:eu-repo/semantics/nonPublishe

Determination of transport and kinetic properties in self-propagating high-temperature synthesis

International audienceExothermic reactions in solid powders are analyzed using the usual macroscopic modeling based on the heat transfer equation coupled to an Arrhenius type of dynamics. This problem have important applications in the synthesis of intermetallics and ceramic materials which occur when a high temperature reaction wave propagates throughout the system. Understanding the mechanism of such processes are thus crucial in mastering real laboratory experiments. We first analyze the model, both theoretically and numerically, for a set of representative parameters. We then use traditional data analyses procedures to estimate from the temperature profiles the same set of representative parameters. Comparison of imposed and estimated values of these parameters allows one to assess directly the limit of applicability and the accuracy of these data analysis approaches. A new strategy is finally derived, which gives a quite good estimate of the activation energy from the measurement of the local temperature profile

Influence of random initial conditions on explosive systems

It has been shown that the exothermal and isothermal explosive systems are extremely sensitive to fluctuations of either thermodynamical and environmental origin as well as to the way they are initially prepared. The latter source of variability, manifested through small differences in initial conditions, can deeply affect the transient behavior. Applied to an exothermic explosive model, like the Semenov model, the effects of random initial conditions manifest themselves in a wide dispersion of explosion times. Furthermore, under certain conditions the distribution of explosion times becomes bimodal: the initial set of systems split, with the same probability, into a short explosion time class and a long explosion time class. © 1991.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Epitaxial growth of the intermetallic compound NiAl on low-index Ni surfaces in Ni/Al reactive multilayer nanofoils

International audienc