Calorimetric and acoustic emission study of the premartensitic and martensitic transitions in Ni–Mn–Ga

• Published in: Materials science & engineering. A, Structural materials : properties, microstructure and processing Vol. 378; no. 1; pp. 353 - 356
• Main Authors: Pérez-Reche, Francisco J, Vives, Eduard, Mañosa, Lluı́s, Planes, Antoni
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Amsterdam Elsevier B.V 25.07.2004; Elsevier
• Subjects: Athermal; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Martensitic transformations; Martensitic transition; Materials science; Ni–Mn–Ga; Phase diagrams and microstructures developed by solidification and solid-solid phase transformations; Physics; Premartensitic transition; Thermally activated; Martensitic transition; Ni–Mn–Ga; Athermal; Thermally activated; Premartensitic transition; Acoustic emission testing; Fluctuations; Nickel alloys; Martensitic transformations; Gallium alloys; Magnetic susceptibility; Manganese alloys; Ni-Mn-Ga; Calorimetry; Activation energy
• DOI: 10.1016/j.msea.2003.10.360
• ISSN: 0921-5093

A study of martensitic and premartensitic transitions in a Ni–Mn–Ga alloy with near stoichiometric composition is reported. We present results from acoustic emission detected during both transitions. Results are complemented with calorimetric and magnetic susceptibility measurements. The effect of thermal fluctuations in both transitions has also been examined. Results suggest that the premartensitic transition has an athermal character whereas the martensitic transition exhibits thermally activated effects. Results for the amplitude distribution of acoustic emission pulses have been obtained for both transitions. No significant differences were found between the exponents corresponding to each transition.