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Abstract

Shape memory materials (for example, nickel-titanium stoichiometric alloys) are able to recover under constant stress the greatest part of their deformation and the related degradation energy; these alloys present moreover a hysteresis in loading-unloading cycles and have the aptitude to present a phase of superelastic behaviour. To observe the mechanical behaviour and damage propagation is often difficult, when aiming to complete indications provided by stress curves with a predictive philosophy. In this paper an analysis performed through the employment of two different techniques, acoustic emission and thermal emission, is presented. The combined use of these two techniques took place during tensile tests on Ni-Ti (49.2%) alloys, whose phase modification plateau is situated around 500 MPa. The two techniques above mentioned are able to supply in real time some indications on damage initiation and fraction modes in the specimens, confirmed by fractographs.

Additional information

Authors: SANTULLI C, JRC Ispra (IT);BILLI F, Università di Roma La Sapienza (IT)
Bibliographic Reference: Paper presented: 11th Colloque International Cercle d'Etudes des Metaux, San Etienne (FR), November 26-27, 1997
Availability: Available from (1) as Paper FR 41046 ORA
Record Number: 199711657 / Last updated on: 1997-12-09
Category: PUBLICATION
Original language: fr
Available languages: fr