Elasticity and Damping Characteristics of SMA Single Crystals, Polycrystals and Thin Films

0387976 - ÚT 2013 IT eng A - Abstract
Landa, Michal - Seiner, Hanuš - Sedlák, Petr - Bodnárová, Lucie
Elasticity and Damping Characteristics of SMA Single Crystals, Polycrystals and Thin Films.
4th International Conference Smart, Material, Structures, Systems. Faenza: Techna Group, 2012. s. 72-72.
[CIMTEC 2012 /4./. 10.06.2012-14.06.2012, Tuscany]
R&D Projects: GA ČR(CZ) GA101/09/0702
Institutional research plan: CEZ:AV0Z20760514
Keywords : elasticity * damping characteristics * ferroelastics
Subject RIV: BJ - Thermodynamics
http://www.cimtec-congress.org/2012/proceedings.asp

We discuss the applicability ultrasonic methods for precise determination of elasticity and damping characteristics of ferroelastics in the form of single crystals, polycrystalline materials and thin films. Particular behaviors of SMAs as are strong elastic anisotropy of single crystals, anomalous temperature dependence of elastic coefficients, their change with magnetic field (ferromagnetic SMAs) natural tendency of martensitic (low-symmetry) phase to form twinned structures as well as texture and fine grains structure of polycrystalline materials induced by technological processing are taken into account to the analysis of mechanical properties of SMAs. It is shown that by using a modal resonant ultrasound spectroscopy (RUS), the fully anisotropic elastic tensor (21 independent coefficients) of textured and micro-structured polycrystals can be determined, from which the symmetry class can be estimated with a search method of mirrors in the elastic tensor. The close correlation between the elastic anisotropy and the spatial arrangement of the grain boundaries in the examined materials is evident. The modified RUS and surface wave propagation (SAW) methods are developed for evaluation of elasticity of thin surface layers. The pros and cons of both approaches are summarized.
Permanent Link: http://hdl.handle.net/11104/0217531