Applying Full-Field Measurement Techniques for the Thermomechanical Characterization of Shape Memory Alloys: A Review and Classification

Abstract

Full-field measurement techniques are now mature. As such, they have profoundly impacted the experimental mechanics community in recent years. The way that shape memory alloys (SMAs) are now tested is not spare from this deep-rooted trend, as reflected by the increasing number of papers published in the SMA literature. In this context, the aim of this contribution is to give an overview of the use of full-field measuring techniques for SMA characterization purposes. We recall first the basic principle of one volume and four surface techniques employed in this community. Several typical papers where such techniques are employed are then presented, by highlighting in each case the extent to which the thermomechanical response of SMAs could be better understood and modeled thanks to these techniques. A classification by several criteria of about 300 references is finally offered and discussed. The main criteria are the type of SMA, the type of technique employed to perform the measurements, and the type of test.

Full-field strain investigation of twinned martensite in a thermally activated Cu–Al–Ni single crystal using Localized Spectrum Analysis

“…In recent decades, full-field measurement techniques have profoundly impacted the community of the mechanics and materials science of SMAs [27]. Indeed, strain and temperature phenomena are generally localized and spatially distributed within a SMA sample, making the use of visible and infrared cameras respectively for analyzing the spatio-temporal kinetics of the phase transformation useful.…”

“…However, the review dating from 2021 in Ref. [27] identified 50 references dealing with DIC measurement on single crystals, among which only 8 concerning Cu-Al-Ni, which is the alloy considered in the present study. Single-crystal samples are more difficult to obtain from suppliers than polycrystal ones.…”

A mechanical criterion for Lüders-type deformation of polycrystalline NiTi

“…The Lüders deformation of NiTi has also been studied by various means in addition to mechanical testing. Video cameras [1,[18][19][20], infrared cameras [1,[21][22][23][24] and digital image correlation (DIC) technique [12,15,23,[25][26][27][28] have been used to observe the macroscopic behaviour of Lüders bands in situ during mechanical testing. Synchrotron X-ray diffraction [29][30][31][32], neutron diffraction [33] and electron backscatter diffraction (EBSD) [34] techniques have also been used to elucidate the phase transformation and microscopic metallurgical processes of the Lüders-type deformation.…”