The shape recovery conditions for Fe–Mn–Si alloys: An interplay between martensitic transformation and plasticity

Journal Article · Tue May 15 04:00:00 EDT 2018 · Materials Characterization

DOI:https://doi.org/10.1016/J.MATCHAR.2018.03.018· OSTI ID:22804990

Vermaut, P. ^[1]; Malarria, J. ^[2]

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1. Groupe de Métallurgie Structurale, UMR CNRS 70 45, ENSCP, 75231 Paris (France)
2. Facultad de Cs. Ex., Ingeniería y Agrimensura (UNR), Av Pellegrini 250, Rosario (Argentina)

Highlights: • Fe15Mn5Si9Cr5Ni samples were rolled at 800 °C and annealed at 650 (C1) and 1000 °C (C2). • TEM analysis was performed. • High density of stacking faults and appropriate density of dislocation appears in C1. • Complex dislocation arrays due to plastic deformation are observed in C2. • Shape memory properties depend on the thermomechanical treatment. - Abstract: This work analyses the improvement of the shape memory properties of Fe-Mn-Si based alloys, and expands upon and deepens recently published developments concerning this topic. We prepared TEM specimens from a Fe-15Mn-5Si-9Cr-5Ni sheet rolled at 800 °C and annealed at 650 °C–92% shape recovery – and from another sheet annealed at 1000 °C–45% shape recovery. Here, we analyse the development of microstructure during the γ ↔ ε martensitic transformation and correlate it with the shape memory behaviour. Among the observed microstructural features, the introduction of complex dislocation arrays due to plastic deformation appears to be critical for shape memory development, since they can arrest the backward movement of Shockley partial dislocations over the original path. Tailoring the microstructure in order to introduce a high stacking-fault density accompanied by an appropriate dislocation density remains a key issue in the design of these kinds of functional materials.

• OSTI ID: 22804990
• Journal Information: Materials Characterization, Journal Name: Materials Characterization Vol. 139; ISSN 1044-5803; ISSN MACHEX
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ANNEALING
DISLOCATIONS
IRON COMPLEXES
MANGANESE COMPOUNDS
MICROSTRUCTURE
PHASE TRANSFORMATIONS
PLASTICITY
SHAPE MEMORY EFFECT
SILICON COMPOUNDS
STACKING FAULTS
TERNARY ALLOY SYSTEMS
THERMOMECHANICAL TREATMENTS
TRANSMISSION ELECTRON MICROSCOPY