Study of the microstructure resulting from brazed aluminium materials used in heat exchangers

Jacques Lacaze (1) , Séverin Tierce (1) , Marie-Christine Lafont (1) , Yannick Thebault (1) , Nadine Pébère (1) , Georges Mankowski (1) , Christine Blanc (1) , Herveline Robidou , David Vaumousse , Dominique Daloz (2)

1 CIRIMAT - Centre interuniversitaire de recherche et d'ingenierie des matériaux
2 LSG2M - Laboratoire de Science et Génie des Matériaux et de Métallurgie

Re-solidification of AA4343 cladding after brazing as well as the related precipitation in the modified AA3003 core material have been investigated. Analysis of the re-solidified material showed that partial dissolution of the core alloy occurs in both the brazing joints and away of them. Far from the brazing joints, the dissolution is, however, limited and diffusion of silicon from the liquid into the core material leads to solid-state precipitation in the so-called “band of dense precipitates” (BDP). On the contrary, the dissolution is enhanced in the brazing joint to such an extent that no BDP could be observed. The intermetallic phases present in the resolidified areas as well as in the core material have been analyzed and found to be mainly cubic alpha-Al(Mn,Fe)Si. These results were then compared to predictions made with available phase diagram information.

Mots clés: Aluminium materials; Heat exchangers; Microstructure; Brazing; Solidification

Domaines: Matériaux

Jacques Lacaze, Séverin Tierce, Marie-Christine Lafont, Yannick Thebault, Nadine Pébère, et al.. Study of the microstructure resulting from brazed aluminium materials used in heat exchangers. Materials Science and Engineering: A, 2005, 413-414, pp.317-321. ⟨10.1016/j.msea.2005.08.187⟩. ⟨hal-03601508⟩