In situ observation of pore evolution during melting and solidification of Al-Pd-Mn quasicrystals by synchrotron X-ray radiography
Résumé
Abstract It is now generally admitted that pores are intriguing special features of quasicrystals. Therefore, we have performed an “in situ” and real time observation of the pore evolution during directional solidification and melting cycles of an icosahedral Al-Pd-Mn bi-grained sample by synchrotron X-ray radiography. Rather surprisingly, no pore was observed to grow during the solidification stages. Nucleation and growth of pores were firstly seen during melting. These pores were subsequently shrinking either just being absorbed or during resumption of directional solidification. It is concluded that the vacancy origin of pores is certainly valid whereas the vacancy supersaturation needed thereby to explain their growth would be more probably related to the peculiar structure of quasicrystal than to the destruction of the thermal equilibrium.
Domaines
Physique [physics]| Origine | Fichiers produits par l'(les) auteur(s) |
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