title: Acoustic emission monitoring of activation behavior of LaNi5hydrogen storage alloy.
abstract: The acoustic emission technique is proposed for assessing the irreversible phenomena occurring during hydrogen absorption/desorption cycling in LaNi5. In particular, we have studied, through a parametric analysis ofin situdetected signals, the correlation between acoustic emission (AE) parameters and the processes occurring during the activation of an intermetallic compound. Decreases in the number and amplitude of AE signals suggest that pulverization due to hydrogen loading involves progressively smaller volumes of material as the number of cycles increases. This conclusion is confirmed by electron microscopy observations and particle size distribution measurements.
authors.affiliation: Department of Chemical Engineering Materials Environment, Sapienza-Università di Roma, Via Eudossiana 18, 00184 Rome, Italy; Present address: Department of Materials Science, University of California Los Angeles, E-V 2122, 410 Westwood Plaza Los Angeles, CA 90095, USA.
authors.forename: Igor Maria
authors.initials: IM
authors.lastname: De Rosa
authors.affiliation: Department DME, Università degli studi 'Guglielmo Marconi', Rome, Italy.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Dell'Era
authors.affiliation: Department of Chemical Engineering Materials Environment, Sapienza-Università di Roma, Via Eudossiana 18, 00184 Rome, Italy.
authors.forename: Mauro
authors.initials: M
authors.lastname: Pasquali
authors.affiliation: Department of Chemical Engineering Materials Environment, Sapienza-Università di Roma, Via Eudossiana 18, 00184 Rome, Italy.
authors.forename: Carlo
authors.initials: C
authors.lastname: Santulli
authors.affiliation: Department of Chemical Engineering Materials Environment, Sapienza-Università di Roma, Via Eudossiana 18, 00184 Rome, Italy.
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Sarasini
keywords: acoustic emission; hydrogen-absorbing materials; intermetallics