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Conference: The liquid metal embrittlement of a reactive system at room temperature: α-brasses in contact with the Ga-In eutectic

03/11/2023 de 12:00 a 13:00
Sala Polivalent de l'edifici I
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Lectured by Dr. Marco Ezequiel, from Laboratoire des Sciences des Procédés et des Matériaux, LSPM -CNRS UPR3407, Paris, France

The talk is titled: “The liquid metal embrittlement of a reactive system at room temperature: α-brasses in contact with the Ga-In eutectic".

Abstract: Liquid metal embrittlement (LME) is a phenomenon where a typically ductile solid metal becomes brittle when in contact with liquid metal. LME depends on factors like chemical composition, strain rate, and the solid/liquid interface. Despite various proposed mechanisms for LME, there is no comprehensive model to predict it. Moreover, limited information is available regarding the embrittlement of reactive metal pairs, and there is an absence of publications on the in situ observation of this phenomenon; our study focuses on these two aspects of LME. Copper and α-brasses were tested with liquid eutectic Ga-In since this system presents intermetallic formation while also being suitable for in situ observations.

Contact conditions were quantified and intermetallic formation was characterized. Different miniaturized mechanical tests at varying strain rates and metallurgical states were performed to understand LME susceptibility. The LME phenomenon was observed in situ at two scales within an SEM. The mechanical conditions during testing were determined using the Finite Element Method, allowing their correlation with the onset of LME.

The conditions that increase LME susceptibility were identified, and the fracture behaviour was characterized in situ and ex-situ. The presence of the intermetallic was found not to influence LME, as it does not hinder contact between the solid and the liquid during plastic deformation. Based on the results, we propose that the mechanisms underlying LME in this system are connected to dislocation mobility.

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