The iron-based Fe–17Mn–5Si–10Cr–4Ni shape memory alloy (SMA) has been manufactured by laser powder bed fusion (LPBF) for the first time. High strength, elongation and ductility are observed after annealing. In addition, pronounced effect (SME) pseudo-elasticity (PE), which exceed those measured conventionally fabricated Fe–17Mn–5Si–10Cr–4Ni-1(V,C) containing VC precipitates, achieved. texture generated during LPBF process brings to SME PE highly dependent on orientation of loading direction...

Abstract The additive manufacturing of shape memory materials, commonly known as 4D printing, facilitates the achievement a complex 3D structure that possesses temperature‐dependent change functionality. Herein, it is demonstrated structures Fe‐based alloys (Fe‐SMAs) can be produced through printing process laser powder bed fusion (L‐PBF). printed Fe‐SMA shows good mechanical properties with much higher strength and stiffness than those in polymers. Fe‐SMAs manifest recovery behavior,...

This study systematically investigated the effects of heat and thermomechanical treatments on pseudo-elastic behavior an Fe-based shape-memory alloy (Fe–17Mn–5Si–10Cr–4Ni-1(V, C) %wt.). First, samples were solution-annealed at 1000 °C for 2 h aged 760 6 h. A treatment was then applied to heat-treated samples. The microstructure mechanical properties (i.e., 0.1% yield stress pseudo-elasticity) characterized using X-ray diffraction, scanning transmission electron microscopy, uniaxial tensile...

This study evaluated the influence of heat treatment and thermomechanical training on microstructural evolution mechanical characteristics conventional additive-manufactured FeMnSi-based shape memory alloys. The samples were produced by casting rolling. manufactured using laser powder bed fusion (L-PBF) technique. Both specimens subjected to same training. involved solution annealing at 1050 °C for 2 h aging 750 6 h, concluded with a 4% elongation ambient temperature followed 250 15 min....

Architected materials exhibit extraordinary properties in comparison with conventional and structures, resulting additional functionality efficiency by engineering the geometry harmony base material. Buckling-induced architected (BIAMs) are a class of that significant potential to absorb dissipate energy owing their local instabilities. Previous studies have shown trade-off between dissipation geometrical recoverability metallic BIAM, which limits use applications require both these...

The phase transformation behavior from metastable bcc-δ to fcc-γ in Fe–Mn–Si based shape memory alloy processed by laser powder bed fusion was investigated. Primary δ formed this due the rapid cooling and fast solidification. Bcc-δ occurred when volumetric energy density high process-inherent heat treatment effect. Transmission electron microscope studies confirmed Kurdjumov-Sachs orientation relationship between phases. analytical results revealed that a combined displacive-diffusional mechanisms.

In the present work, a Fe–Mn–Si shape memory alloy containing V and C has been fabricated by laser powder bed fusion for first time. A pronounced pseudo-elasticity compared to similar but conventionally manufactured is achieved after aging treatment, as result of fine microstructure developed during process evaporation Mn. The formation high precipitate densities also responsible improved thermo-mechanical properties. size density precipitates significantly vary with conditions account...

The fcc-γ → hcp-ε bcc-α' martensitic transformation of a Fe-Mn-Si-based shape memory alloy fabricated by laser powder bed fusion (LPBF) is studied for the first time in-situ neutron diffraction, high-resolution electron backscatter diffraction and digital image correlation during uniaxial tensile testing. comparison between horizontal specimens (fabricated with no inclination on build platform) vertical 90° shows that sample orientation affects deformation behavior material, considerably...

This study investigates the microstructure and properties of functionally graded NiTi alloy bilayers. The layer is printed by laser powder bed fusion on a NiTiX (where X Hf or Cu) substrate prepared vacuum arc remelting. Specimens produced with different thicknesses layers, but constant thickness ratio, are examined optical scanning electron microscopy prior to postannealing process at 1000 °C for 16 h. Scanning microscopy– energy‐dispersive X‐ray spectroscopy transmission studies reveal...

This work demonstrates the tailoring of microstructure two FeMnSi-based shape memory alloys during laser powder bed fusion. Significant variations in parts can be induced by modifying scanning speed or strategy process. Specifically, volume phase fractions, texture, and grain size morphology change with applied processing parameters as thermal history experienced material is modified. Additionally, generally undesired Mn evaporation melting deliberately exploited to manipulate composition...

This work demonstrates the tailoring of microstructure two FeMnSi-based shape memory alloys during laser powder bed fusion. Significant variations in parts can be induced by modifying scanning speed or strategy process. Specifically, volume phase fractions, texture, and grain size morphology change with applied processing parameters as thermal history experienced material is modified. Additionally, generally undesired Mn evaporation melting deliberately exploited to manipulate composition...

Fe-Mn-Si shape memory alloys are materials, whose functional properties strongly depend on microstructural factors such as grain size and orientation, phase fraction chemical composition. The present study demonstrates the possibility of microstructure modification via process parameter variation a based alloy fabricated by laser powder bed fusion. By varying scan speed, samples characterized coarse elongated grains with strong <001> orientation along build direction or finer equiaxed...

3D Printed Fe-Shape Memory Alloys In article number 2200171, Dohyung Kim, Irene Ferretto, Christian Leinenbach and Wookjin Lee demonstrate 4D printing of Fe-based shape memory alloy using laser powder bed fusion technique for the first time. Integrating material-inherent functionalities into complex structures allows new including morphing, metal-material behavior, extraordinary specific strength with behavior.

The fcc-γ→hcp-ε→bcc-α' martensite transformation of a Fe-Mn-Si-based shape memory alloy fabricated by laser powder bed fusion is studied in-situ neutron diffraction, high-resolution electron backscatter diffraction and digital image correlation during uniaxial tensile testing. investigated samples are with different orientations on the build plate so that loading direction parallel (vertical) perpendicular (horizontal) to direction. orientation sample respect plays an important role in...

Abstract The determination of the amount and distribution different phase fractions in additively manufactured shape memory alloys processed with laser powder bed fusion is crucial for understanding correlation between processing parameters, microstructure, mechanical properties. Neutron imaging techniques, such as Bragg edge polarization contrast neutron (PNI), have been introduced to complement overcome limitations traditional characterization methods, which are often destructive limited...