WIAS Preprint No. 251, (1996)

Phase Transitions of Shape Memory Alloys in Soft and Hard Loading Devices



Authors

  • Schwarz, Michael

2010 Mathematics Subject Classification

  • 34A09 34A50 82D25

Keywords

  • Phase Transitions, Shape Memory Alloys, Rate Laws

Abstract

Shape memory alloys exhibit a complex load deformation temperature behaviour (especially e.g. hysteresis and "inner" loops) which is due to the occurence of a first order phase transition.

By load deformation diagrams the so-called shape memory effect can be made visible.

We study a model of I. Müller et al. [1], based on statistical mechanics, which is applicable to biaxial loading of polycrystalline bodies and incorporates the rotational part of a deformation. Recently, I. Müller et al. [3] have proposed a second model incorporating the coherence energy for solid phase mixtures. For two principle variants of experiments (soft and hard loading devices) we present numerical simulations of load deformation curves for either of the two models. Comparing these with experimental results of so-called "inner loops" in a hystersis the second model shows its superiority.

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