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arXiv · 2502.18037

Listen! It's a phase transition. The sound of a shape-memory alloy

Carlo Andrea Rozzi·Annamaria Lisotti·Guido Goldoni·Valentina De Renzi
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Abstract

Shape-memory alloys exhibit a solid-to-solid phase transition that involves a temperature-driven rearrangement of their crystal structure and is responsible for their remarkable properties and numerous technological applications. Here, we propose a simple experiment that analyzes the sound emitted by a Ni$_{40}$Ti$_{50}$Cu$_{10}$ bar at different temperatures as it undergoes a transition between its austenite and martensite phases. We show that the phase transition, which occurs slightly above room temperature, can be qualitatively detected by the ear and quantitatively described using a very simple experimental setup and sound analysis tools. Such a sound-based investigation provides an unusual and engaging way to experimentally introduce solid-to-solid phase transitions, that is suitable for undergraduate courses.

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Carlo Andrea Rozzi, Annamaria Lisotti, Guido Goldoni, Valentina De Renzi. 2025-02-25. Listen! It's a phase transition. The sound of a shape-memory alloy. https://doi.org/10.1119/5.0217522

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