2007/11/07 by Mathieu Bouville, Rajeev Ahluwalia
Materials Science · Physics and Astronomy · #Microstructure and mechanical properties #Shape Memory Alloy Transformations #Solidification and crystal growth phenomena #cond-mat.mtrl-sci
paper · pdf · doi:10.1016/j.actamat.2008.03.041
published as Acta Materialia 56(14), 3558 (2008) · 10 pages, 27 figures
arxiv created 2007/11/07 · openalex publication_date 2008/05/01 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/29
We use the phase-field method to study the martensitic transformation at the nanoscale. For nanosystems such as nanowires and nanograins embedded in a stiff matrix, the geometric constraints and boundary conditions have an impact on martensite formation, leading to new microstructures --such as dots aligned on a square lattice with axes along <01>-- or preventing martensite formation altogether. We also perform tension tests on the nanowires. The stress-strain curves are very different from bulk results. Moreover, they are weakly affected by microstructures -- the mechanical response of nanowires with different microstructures may be similar, while nanowires with the same microstructure may have a different mechanical behavior. We also observe that at the transition temperature, or slightly below it, the narrowest wires behave pseudoelastically whereas wider wires are in the memory-shape regime. Moreover the yield stress does not change monotonically with width: it has a minimum value at intermediate width.