Building hierarchical martensite

Abstract

Martensitic materials show a complex, hierarchical microstructure containing structural domains separated by various types of twin boundaries. Several concepts exist to describe this microstructure on each length scale, however, there is no comprehensive approach bridging the whole range from the nano- up to the macroscopic scale. Here, we describe for a Ni-Mn-based Heusler alloy how this hierarchical microstructure is built from scratch with just one key parameter: the tetragonal distortion of the basic building block at the atomic level. Based on this initial block, we introduce five successive levels of nested building blocks. At each level, a larger building block is formed by twinning the preceding one to minimise the relevant energy contributions locally. This naturally explains the occurrence of different types of twin boundaries. We compare this scale-bridging approach of nested building blocks with experiments in real and reciprocal space. Our approach of nested building blocks is versatile as it can be applied to the broad class of functional materials exhibiting diffusionless transformations.

arXiv comment25 pages, including supplementary

References in corpus (9)

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Cited by in corpus (6)

• Kwinking as the plastic forming mechanism of B19' NiTi martensite
• What is the speed limit of martensitic transformations?
• Influence of Gd-rich precipitates on the martensitic transformation, magnetocaloric effect and mechanical properties of Ni-Mn-In Heusler alloys -- A comparative study
• Compliant Lattice Modulations Enable Anomalous Elasticity in Ni-Mn-Ga Martensite
• On Scaling Laws for Multi-Well Nucleation Problems without Gauge Invariances
• Shear Deformation of Nonmodulated Ni${}_2$MnGa Martensite: An Ab Initio Study