Listening to a phase transition: Acoustic probing of the martensitic transition

We propose a novel educational experimental path to explore the austenite-to-martensite phase transition in a NiTiCu alloy. By analyzing the sound produced when striking a NiTiCu bar across the transition temperature, we quanti- tatively probe the material mechanical properties and phase coexistence. This acces- sible experiment combines acoustic analysis with fundamental concepts in materials science, providing an engaging way to approach phase transitions in undergraduate curricula.