Effect of Phase Changes on the Axial Modulus of an FeMnSi-Shape Memory Alloy

• Main Authors: Yajiao Yang, Matteo Breveglieri, Moslem Shahverdi
• Format: Article
• Language: English
• Published: MDPI AG 2021-08-01
• Series: Materials
• Subjects: FeMnSi-based shape memory alloys; axial modulus <i>E_SMA</i>(<i>κ</i>); activation process; phase transformation; plastic deformation
• Online Access: https://www.mdpi.com/1996-1944/14/17/4815

The axial modulus <i>E_SMA</i>(<i>κ</i>) of FeMnSi-based shape memory alloys (FeMnSi-SMAs) is a parameter introduced in this study to characterize the relationship between stress and strain behavior at the early stage of tensile loading. <i>E_SMA</i>(<i>κ</i>) can be used to correctly estimate and model the interaction forces between FeMnSi-SMAs and other materials. Unlike the conventional Young’s modulus, which is usually given at room temperature, the <i>E_SMA</i>(<i>κ</i>) is evaluated at different temperatures and strongly depends on phase transformation and plastic deformation. This study investigated the evolution of <i>E_SMA</i>(<i>κ</i>) during and after pre-straining as well as in the course of the activation processes. The effect of different factors (e.g., phase transformation and plastic deformation) on the magnitude of <i>E_SMA</i>(<i>κ</i>) is discussed. The result shows that the <i>E_SMA</i>(<i>κ</i>) can differ significantly during activation and thus needs to be modified when interaction forces between FeMnSi-SMAs and other substrates materials (e.g., concrete) must be modeled and evaluated.