0000000000002114
AUTHOR
Ginette Watelle
Transformation structurale associée à la réaction de décomposition des hydroxydes de type brucite
Dans le contexte de la preparation de solides finement divises (oxydes pour les ceramiques pour l'electronique, precurseurs de metaux divises, metaux divises,...) par des methodes dites de "chimie douce" l'exemple d'une reaction de decomposition endothermique d'un solide tres largement etudiee est repris par le biais d'une etude de l'evolution morphologique et texturale du solide produit en fonction de la vitesse de la reaction. Les caracteres -dimension, distribution des tailles et formes des grains- dependent tres largement du couple precurseur produit.
Instability and bistability during the growth of a corrosion scale on metals and alloys
This paper summarizes the main results for the interpretation of the self organized corrosion scales observed in oxidation or sulfidation of some metals or alloys. It consists also of a reconsideration of the classical theoretical concepts used in Reactivity of Solids. It proposes new theoretical tools that have been fruitfully utilized in other topics : non linear and coupled processes, stability analysis and bifurcation theory. Some examples are developed, where the corrosion kinetics at high temperature are interpreted in term of chemical bistable system able to oscillate spontaneously and mechanochemical couplings are also taken into account. In according with experimental results, all …