J. Phys. IV France 12 (2002) Pr8-289
DOI: 10.1051/jp4:20020341

Liquid metal penetration at grain boundaries: Characterization by synchrotron radiation micro-radiography and micro-fluorescence

W. Ludwig¹, D. Bellet², J. Teyssier², J. Ouillier², N. Marie³, K. Wolski³, A. Simionovici¹ and C. Rau<sup>1

1</sup>  European Synchrotron Radiation Facility, BP. 220, 38043 Grenoble, France
²  Laboratoire Génie Physique et Mécanique des Matériaux, ENSPG, BP. 46, 38402 Saint-Martin-d'Hères cedex, France
³  Centre SMS/MPl, Ecole des Mines de Saint-Etienne, 42023 Saint-Etienne cedex 02, France

Abstract
The penetration of liquid metals into the gain boundaries (GB) of solid metals in the absence of external stress is a process which, in the case of some specific couples, can lead to severe embrittlement ofthe solid. We present in this paper two synchrotron radiation (SR) X-ray imaging techniques, which are well adapted for the non-destructive bulk characterization of this type of phenomena. Synchrotron radiation X-ray micro-radiography was used to characterize the liquid metal penetration kinetics in the Al/Ga system. It was shown that this modern variant of absorption radiogaphy provides sufficient spatial and temporal resolution to observe the penetration of sub-micrometric liquid Ga films into the grain boundaries of Al bicrystals. Synchrotron radiation X-ray micro-fluorescence on the other hand is well suited for the element specific characterization of extremely dilute systems. At the expense of temporal and spatial resolution, this technique allows one to detect minute quantities of atoms, diffusing along the GB of solid metals.

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