CHANGEMENTS DE PHASES ET MICROSTRUCTURES
J. Phys. IV France 04 (1994) C3-127-C3-132
Les mécanismes de l'oxydation interne dans les alliages à base d'argentL. CHARRIN, A. COMBE, A. CHARAI and J. CABANE
Laboratoire de Métallurgie, EDIFIS, associé au CNRS, Faculté des Sciences et Techniques de Saint Jérôme, Case 511, 13397 Marseille cedex 20, France
Internal oxidation mechanism in silver alloys was studied by residual resistivity, gravimetric and calorimetric measurements, X-Ray diffraction and by transmission electron microscopy. It has been established in Ag-Mg alloys that the oxygen fixation process involves three steps : firstly, substoichiometric species are initially formed ; secondly these elementary species evolve toward irregular clusters including an important excess of oxygen ; thirdly, a part of this excess oxygen is released and clusters evolve toward a more compact structure. The mechanism of internal oxidation in Ag-Mg alloys can be generalized to the other studied alloys such as Ag-Cu, Ag-Zn and Ag-Sn.
© EDP Sciences 1994