Work-hardening Rate Research Articles

Phase equilibria, martensitic transformations and deformation behaviors of the subsystem of Cantor alloy−low-cost Fe-Mn-Cr alloys

Investigations of the Fe-Mn-Cr system are not only significant for developing Cantor alloy but also valuable for designing low-cost, high-strength steel. In this study, we experimentally determined the phase equilibria of this system for establishing the thermodynamic database. Additionally, the influences of Mn on both the phase transformation and deformation behaviors of the Fe-Mn-Cr alloys were studied. Fe was found to solute into σHT phase with a large solubility at 1323 and 1473 K. A (βMn) single-phase region was initially discovered at 1473 K. The (βMn)+(γFe) and σHT+(Cr) two-phase regions were respectively found to be very narrow. During tensile testing, the transformation-induced-plasticity (TRIP)- type was discovered to change from ε→α′ to (γFe)→ε when Mn increased from 20 to 30 at. %. The stacking fault energy (SFE) was measured to be 8.1 mJ·m−2 for 30Mn alloy. Contrarily, the stacking fault did not seem to occur during the tensile testing of 40Mn alloy. The 0.2 % proof stresses for Fe(90-x)MnxCr10 alloys were measured to be 633 (10Mn), 345 (20Mn), 166 (30Mn), and 188 MPa (40Mn), respectively. The TRIP effect was discovered in the tensile testing of 30Mn alloy, which exhibited an ultimate tensile strength of 755 MPa and a uniform elongation of 38.7 %. It is to be noted that no recovery of work-hardening rate occurred during the tensile testing of 40Mn alloy. The investigated phase equilibria and deformation behaviors of the Fe-Mn-Cr alloys are believed to accelerate the design of Cantor-alloy-related materials and Fe-Mn-Cr-based high-strength steel.

Deformation mechanism and microstructure evolution of medium-Mn AHSS under various loading conditions

Third-generation advanced high-strength steels possess an exceptional combination of high strength and ductility owing to their high work-hardening rate during deformation. In this study, the mechanical properties and microstructure/texture evolution of medium-Mn steel under various loading conditions (uniaxial tension, in-plane torsion, and equibiaxial tension) were investigated. Interrupted electron back-scattered diffraction and X-ray diffraction characterizations were carried out to track the microstructure and texture evolution of individual phases. Digital image correlation was employed for the in-situ measurement of formation and expansion of deformation bands, i.e., the Lüders and the Portevin-Le Châtelier (PLC) bands. The dynamic strain aging effect in terms of the formation of PLC bands and stress serrations was significantly affected by the loading conditions and stress level. Multiple types of stress serrations were observed in all tested specimens at different deformation stages. The texture evolution of the steel under various deformation modes was further tracked. Ferrite and fresh martensite exhibited the plain texture evolution like most body-centered cubic metals, whereas austenite showed a more complex texture evolution. The martensitic transformation notably decreased the RD||<001> intensity of the austenite; austenite debris was rotated with ferrite grains, while some intact austenite grains self-rotated to a stable orientation, which is unfavorable for martensitic transformation. The obvious intragranular orientation gradient observed in the austenite intact grains implies that considerable deformation occurred in the austenite. Finally, the experimental results indicate that equibiaxial tension primarily promoted the martensitic transformation, and the classical Olson–Cohen model was calibrated to capture the volume fraction evolution of austenite under various stress states.

Improving the ultimate tensile strength without loss of plasticity of quenching-partitioning steel by introducing hot deformation

Quenching and partitioning (Q&P) is a heat treatment process which can obtain high strength and good plasticity matching steels. In this study, hot axial rolling was introduced in the Q&P steel and the microstructure evolutions and mechanical behaviors were compared with traditional Q&P steel. The results show that the introduction of hot deformation can retain more austenite, produce higher dislocation density and promote the precipitation of transition carbides. The higher dislocation density and more closely spaced transition carbides increase the work-hardening rate, which can not only increase the ultimate tensile strength, but also ensure no loss of plasticity, that is, improve the comprehensive mechanical properties of the Q&P steel.

Constitutive modeling, computational implementation and material parameter identification for polymeric foams considering density and foaming direction

Polyurethane foam (PUF) is a porous material and significantly affected by compressive loads. Under a uniaxial compressive load, the PUF exhibits various types of material nonlinear behavior under varying conditions, such as density, foaming direction, and strain rate. This study investigates the nonlinear behavior of a PUF through phenomenological approach. A Frank–Brockman–Zairi elasto-viscoplastic constitutive model was adopted to investigate the behavior of PUFs with different densities, directions, and strain rates when subjected to compressive loads. The proposed model was discretized using the implicit time integration algorithm and implemented into a user-defined subroutine of ABAQUS. In this study, parameter determination method was also implemented to identify material parameters containing the constitutive equations. Furthermore, the detailed process of determining the material parameters containing the shape of the work-hardening rate–stress curve dependent on the type of material behavior was presented. Consequently, the macroscopic material response of the PUF, such as the stress–strain curve, can be predicted based on the proposed constitutive model. In future studies, the mechanical behavior of porous materials can be analyzed more successfully by supplementing the constitutive model. This can allow the model to simulate the complex plastic flow of porous materials after yielding that is presently difficult to implement.

Superior strength-ductility in laser aided additive manufactured high-strength steel by combination of intrinsic tempering and heat treatment

ABSTRACT This work investigated laser aided additive manufacturing (LAAM) high-strength steel by leveraging the intrinsic tempering effect to facilitate the formation of high-fraction of metal carbides (e.g. M23C6 and M7C3) in the as-built samples. The intrinsic tempering effect contributes to a superior mechanical property than traditional manufacturing methods in as-built condition, promoting subsequent heat treatments (HTs) for excellent mechanical properties. The influence of HTs on the microstructures and mechanical properties were characterised in multi-scales. A large number of carbides are intrinsically formed due to the tempering effect during deposition. The high-density dislocations in the as-built sample facilitate the formation of massive nano-twins and carbides during HT. The HTed sample achieves a true tensile stress of about 1.81 GPa together with a true strain of about 21%, achieving an excellent strength-ductility combination compared to wide-range high-strength steels processed by additive manufacturing and conventional methods. The grain and twin boundaries strengthening, precipitation strengthening and dislocation strengthening contribute to the high strength, while the good ductility originates from twinning induced plasticity (TWIP) and transformation-induced plasticity (TRIP) effects, and high work-hardening rate, during deformation. The findings imply a potential way to develop AM-customised materials by fully understanding and utilising the IHT effect.

Remarkable improvement in tensile strength of a polycrystalline γ-TiAl-based intermetallic alloy by deformation nanotwins

Strengthening of TiAl-based intermetallic alloy is vital for its broader application, however, microstructural refinement through conventional processes is difficult to further strengthen this intermetallic alloy. Although high-density deformation nanotwin is expected to effectively strengthen it, there is still lack of in-depth understanding about the strengthening mechanism of high-density deformation nanotwin in TiAl-based alloy. Herein the microstructures, room-temperature (RT) tensile properties, tensile fracture behavior, and deformation mechanism of the Ti-45.5Al–4Cr-2.5Nb (at.%) master alloy (M. A.) as well as its continuous casting (C. C.) alloy and the heat-treated alloys were systematically investigated. After the C. C. alloy was annealed at 1250 °C for 2 h, the volume fraction of (B2+γ) coupled structures in the original grains reached the minimum, the interlamellar spacing was markedly refined; besides, substantial Shockley partial dislocations and stacking faults were generated in γ phase. During RT tension, both the dominant deformation mechanisms of the M. A. and C. C. alloy were dislocation slip, while that of the 2 h heat-treated alloy was changed into deformation twinning. High-density deformation nanotwins were generated in the γ phase (especially the γ lamellae) of the 2 h heat-treated alloy, which improved the tensile strength of the M. A. by 79%. High-density deformation nanotwins can further strengthen TiAl-based alloy to a large extent, which is mainly attributed to the fact that their batch-to-batch generation in the polycrystalline TiAl-based alloy during tension could considerably relief the stress concentration in addition to effectively improving the work-hardening rate, thus making the work-hardening rate keeping stable.

Tensile Deformation of Si Single Crystals with Easy Glide Orientation

Silicon single crystals were deformed in tensile tests along the [134] direction between 1173 K and 1373 K. The yield point phenomenon was observed in the specimens deformed below 1273 K, while a continuous yield was observed in the specimens deformed above 1323 K. The values of work-hardening rate in stage II were the same as those reported in other single crystals. Orientation maps of the specimen obtained by using electron backscattered electron diffraction method indicated that stage II starts before the Schmid factor of the secondary slip system became larger than that of the primary slip system. Because of the constraint due to the gripping of the test piece, kink bands are formed during stage I before the onset of stage II, and then the stress state becomes non-uniaxial. This suggests that the formation of kink bands triggers the activation of the secondary, i.e., conjugate slip system to increase the resolved shear stress on the conjugate slip systems.

Effects of Grain Size, Thickness and Tensile Direction on Ductility of Pure Titanium Sheet

The effects of the thickness (t), grain size (d), ratio t/d, and tensile direction on tensile properties were carefully examined using ASTM grade 1 pure titanium having a strong B texture with the controlled thickness (0.2–0.4 mm), grain size (20–175 µm), and t/d (2.3–19.4). 0.2%-proof stress followed a Hall-Petch relationship in each tensile direction regardless of thickness, and this indicates that 0.2%-proof stress does not depend on t/d. On the other hand, tensile strength and uniform elongation were confirmed to depend on t/d and significantly decreased in some thin sheets, compared to thick sheets with the same grain size, except for the case tested in the transverse direction. Namely, both tensile strength and uniform elongation exhibited a drastic decrease when t/d becomes smaller than the critical values. The critical value of t/d depended on tensile direction and decreased with an increasing tensile angle in the rolling direction. Local elongation increased with decreasing grain size except for the case tested in the transverse direction. In addition, local elongation was not related to t/d. Tensile properties that depend on t/d are inferred to be affected by work-hardening behavior, enhanced by twinning deformation in hcp titanium. However, the formation of deformation twinning in the surface regions was found to be suppressed, presumably due to the relaxed, constrained conditions. Consequently, the work-hardening rate decreased with decreasing t/d because of the attribution from the surface region where twinning deformation is retarded. This Paper was Originally Published in Japanese in J. Japan Inst. Met. Mater. 84 (2020) 227–236.

Effect of minor Ce and Zr on the wear property of a nickel-saving austenitic heat-resistant cast steel

ABSTRACT In this work, the effect of Ce and Zr on the wear performance of a nickel-saving austenitic heat-resistant cast steel at room temperature and 900 °C are investigated. The wear mechanism and strengthening mechanism played by the addition of Ce and Zr are also discussed. The enhanced work-hardening rate after adding Ce and Zr strengthens the worn surface during wearing and improves the wear resistance of the nickel-saving austenitic steel at room temperature. The addition of Ce and Zr reduces the dynamic recovery and recrystallisation softening effect, which is the main reason for improving the high-temperature wear performance of the nickel-saving austenitic steel. Besides, the wear-protective glaze layer formed on the worn surface of Ce- and Zr-containing alloys could also reduce the high-temperature wear of the nickel-saving austenitic steel.

Effect of oxygen content on the mechanical properties and plastic deformation mechanisms in the TWIP/TRIP Ti–12Mo alloy

In the last decades, biomaterials have improved the life and its quality for millions around the Globe. Titanium-based biomaterials have rapidly become the gold standard for bone contact applications. Despite their successful performance, their low strength-ductility trade-offs and work-hardening rates limit their use for example for the manufacture of vascular stents. Although a high strength-ductility trade-off and a high work-hardening rate were reported for the TWIP/TRIP Ti–12Mo alloy, strengthening strategies are required to approach its strength to the ones of Co–Cr alloys, main metallic materials used to produce stents. In this study, the investigated strengthening strategy was the increase of oxygen content from 0.04 to 0.18 wt% in the Ti–12Mo alloy. The effect of this increase on its microstructure, mechanical properties and plastic deformation mechanisms was studied. Athermal ω precipitates were observed throughout with the β matrix of both solution-treated alloys. X-Ray diffraction and transmission electron microscopy suggested that the quantity of ω phase was larger in the alloy with a higher oxygen content, contrasting with the common knowledge that O suppresses ω phase precipitation. Independently of oxygen content, {332}<113> twins and stress-induced martensite (SIM) α" occurred in the deformed microstructures. Based on the electron backscatter diffraction analyses, the area fraction of SIM α" decreased by increasing oxygen content. Although elongation decreased with this oxygen content increase, Ti–12Mo-0.18O exhibited a high true uniform elongation of 25% and a true ultimate tensile strength higher than the Ti–12Mo-0.04O alloy. Hardness and yield strength also increased by increasing oxygen content, while elastic modulus did not change.

Work hardening behavior of dual phase copper–iron alloy at low temperature

In-situ neutron diffraction measurements were performed on a cold-rolled copper-iron (Cu–Fe) alloy during tensile tests at 293 K and 150 K. The alloy was composed of face-centered cubic Cu and body-centered cubic Fe. The roles of Cu and Fe on the deformation behavior of alloys were discussed and clarified. The strength and work-hardening rate of the alloy increased with decreasing test temperature. Furthermore, the phase stress of Fe increased considerably with decreasing test temperature; however, the response of this stress to the applied true stress exhibited no dependence on the temperature. The phase stresses of Cu changed only slightly with decreasing test temperature. However, the Cu phase stress response to the applied true stress increased with decreasing test temperature, indicating an increase in the work-hardening rate. The strengthening of Fe and the increase in the work-hardening of Cu contributed to an increase in the strength and work-hardening rate of the Cu–Fe alloy at low temperatures.

Accommodation mechanisms in strain-transformable titanium alloys

A new β-metastable Ti-alloy is designed with the aim to obtain a TWIP alloy but positioned at the limit between the TRIP/TWIP and the TWIP dominated regime. The designed alloy exhibits a large ductility combined with an elevated and stable work-hardening rate. Deformation occurring by formation and multiplication of {332}<113> twins is evidenced and followed by in-situ electron microscopy, and no primary stress induced martensite is observed. Since microstructural investigations of the deformation mechanisms show a highly heterogeneous deformation, the reason of the large ductility is then investigated. The spatial strain distribution is characterized by micro-scale digital image correlation, and the highly deformed regions are found to stand at the crossover between twins, or at the intersection between deformation twins and grain boundaries. Detailed electron back-scattered imaging in such regions of interest finally allowed to evidence the formation of thin needles of stress induced martensite. The latter is thus interpreted as an accommodation mechanism, relaxing the local high strain fields, which ensures a large and stable plastic deformation of this newly designed Ti-alloy.

A multiscale constitutive model coupled with martensitic transformation kinetics for micro-scaled plastic deformation of metastable metal foils

The mechanical behavior of metastable austenitic foils at the size scale from micron to submillimeter is strongly affected by the coupling between size effect and strain-induced martensitic transformation (SIMT), which remains to be a pressing issue to be explored. In this research, the focus is on developing a multiscale constitutive model to reveal the mechanical behavior of metastable foils and more accurately predict the size effect on SIMT. In tandem with this, the martensitic transformation and hardening behavior of SUS304 foils with different thicknesses and grain sizes were explored. The results figured out that the SIMT is promoted by the increase in grain size and foil thickness. Furthermore, the onset and end of stages II of work-hardening behavior are advanced and the work-hardening rate in stage II increases faster with increasing grain size and foil thickness. The SIMT kinetic model was coupled with the intermediate mixture law and the iso-work hypothesis to identify the stress-strain relationship of individual austenite and martensite at the surface and interior layers, which was used to construct the multiscale constitutive model. The multiscale model was developed based on the framework of the surface layer model and the intermediate mixture law to represent the coupling between the size effect and the SIMT. Through finite element simulation by using the proposed multiscale constitutive model, the dispersion hardening mechanism in micro-scaled deformation of metastable austenitic foils caused by the non-homogeneous plastic deformation at the interface between austenite and martensite was revealed. The multiscale model was validated via the corroboration of finite element simulation with experiments and therefore can provide a robust analysis of the micro-scaled deformation behavior of metastable austenitic foils.

Microstructural Evolutions, Hot Deformation and Work Hardening Behaviour of Novel Al–Zn Binary Alloys Processed by Squeezing and Hot Extrusion

The main goals of this work were to manufacture novel Al–Zn extruded alloys by varying the Zn content (0, 10, 20, 30 wt%), investigate the microstructural evolutions, hot deformation, and work hardening behaviour by hot compression test at different temperatures (25 °C, 75 °C, 150 °C, 225 °C, 300 °C). Al–20Zn alloy microstructure revealed α-Al and uniform distribution of (α + η) phases, coherent (α + η) crystals in GBs with casting defect-free surfaces, and effective interactions of pinning dislocations which led to improve mechanical performance of Al–20Zn alloy, as compared to the other alloys. The observed engineering stress–strain curve results revealed the decrease of stress with increasing of temperature due to flow softening, dynamic recovery and dynamic recrystallization. These results displayed also an increase of stress value with increasing of Zn content due to the precipitation of high density (α + η) phase in the matrix and GBs, increasing of forest and mobile dislocations density with strain fields, and the formation of fine dendrites. Work hardening rate (WHR) of extruded samples displayed three stages: stage I, WHR decreased slightly with increasing of temperature up to 75 °C and decreased drastically from 75 °C to 300 °C due to softening; stage II, WHR maintained constant due to balance between dislocation generations and dislocation annihilation; stage III, WHR slightly increased due to strain hardening of (α + η) phase. WHR was observed to increase considerably with increasing of Zn content due to the formation and dispersion of high density of (α + η) phase in the Al matrix and GBs. Deformation micro-localization in terms of different characteristics was examined and reported on the deformed samples after hot-compression test through SEM micrographs.

Enhancement of fatigue resistance of additively manufactured 304L SS by unique heterogeneous microstructure

ABSTRACT Selective laser melting (SLM), as a revolutionary technology for metal manufacturing, attracts tremendous attention because it can produce complex components to benefit the customised production. Here we report that additively manufactured 304L austenitic stainless steel (SS) with low stacking fault energy (SFE) show superior fatigue resistance than its conventional counterparts due to the unique heterogeneous microstructure despite containing relatively high porosity. A series of detailed microstructural characterisations were applied to systematically disclose the fatigue enhancement mechanism of additively manufactured parts. Direct evidence is offered to show the obvious progressive work hardening and strain rate hardening caused by the heterogeneous microstructure during cyclic deformation, thus enhancing the fatigue crack initiation resistance. The microstructural results reveal that the cellular substructure plays a decisive role in regulating the dislocation motion during cyclic deformation, resulting in the intergranular fatigue cracking along HAGBs rather than twin boundaries.

Tensile Deformation of Si Single Crystals at High Temperatures

Czochralski silicon single crystals were deformed in tensile tests along the direction at between 1173 K and 1373. Yield point phenomenon were observed in the specimens deformed at below 1273 K while continues yield was observed in the specimens deformed at above 1323 K. It is due to the effect of dislocation starvation in the used crystals. Work-hardening rates in stage II were consistent with those reported in fcc crystals such as copper. The onset of stage II was found to be active before the Schmid factor of the second slip system becomes larger than that of the primary slip system. Electron backscattered diffraction images indicated clear kink bands near grips and in the parallel portion. The kink bands were formed at the middle of stage I, which suggest that the formation of kink bands is a trigger of stage II.

High-Density Deformation Nanotwin Further Improved Tensile Strength of Polycrystalline γ-TiAl-Based Intermetallic Alloy

Strengthening of TiAl-based intermetallic alloy is vital for its broader application, however, microstructural refinement through conventional processes is difficult to further strengthen this intermetallic alloy. Although high-density deformation nanotwin is expected to effectively strengthen it, there is still lack of in-depth understanding about the strengthening mechanism of high-density deformation nanotwin in TiAl-based alloy. Herein the microstructures, room-temperature (RT) tensile properties, tensile fracture behavior, and deformation mechanism of the Ti-45.5Al-4Cr-2.5Nb (at.%) master alloy (M. A.) as well as its continuous casting (C. C.) alloy and the heat-treated alloys were systematically investigated. After the C. C. alloy was annealed at 1250 °C for 2 hours, the volume fraction of (B2+γ) coupled structures in the original grains reached the minimum, the interlamellar spacing was markedly refined; besides, substantial Shockley partial dislocations and stacking faults were generated in γ phase. During RT tension, both the dominant deformation mechanisms of the M. A. and C. C. alloy were dislocation slip, while that of the 2h heat-treated alloy was changed into deformation twinning. High-density deformation nanotwins were generated in the γ phase (especially the γ lamellae) of the 2h heat-treated alloy, which improved the tensile strength of the M. A. by 79%. High-density deformation nanotwins can further strengthen TiAl-based alloy to a large extent, which is mainly attributed to the fact that their batch-to-batch generation in the polycrystalline TiAl-based alloy during tension could considerably relief the stress concentration in addition to effectively improving the work-hardening rate, thus making the work-hardening rate keeping stable.

Simultaneous enhancement of strength and ductility in ferrite-martensite steel via increasing the martensite fraction

In the current research, the effect of intercritical annealing temperature on the microstructural evolution and mechanical properties of dual-phase (DP) steel was investigated. The results showed that a homogeneous distribution of martensite in the ferrite caused by performing the asymmetric rolling before the intercritical annealing. By increment of the temperature of intercritical annealing to 830 °C, the volume fraction of martensite increased to 0.68. The DP770 and DP830 steels had the plate and lath martensite, respectively. Interestingly, both strength and ductility remarkably increased with increasing of martensite fraction owing to the decrement of martensite carbon concentration. Increasing the yield and ultimate tensile strengths (YS and UTS) was more than 174% and 130% in comparison with the as-received steel, respectively. There was a strong linear relationship (with R-squared more than 0.95) between the tensile properties and the martensite fraction. When the temperature of annealing increased, the rate of work hardening enhanced, especially in the early stages of plastic deformation, due to the increment of martensite fraction in the microstructure. The DP830 steel has one stage of strain hardening, which was owing to the improvement of strain hardening ability of the martensite phase caused by the lower carbon content. The results of the current research exhibited that the failure mode of DP steels was a mixture of brittle and ductile fractures, however, the DP830 steel has a more ductile fracture. The decreasing the hardness difference between ferrite and martensite in DP steels decreased the severity of interface decohesion and delayed void formation and fracture during the tensile deformation.

Nondestructive tests on the effect of Mg content on the corrosion and mechanical properties of 5000 series aluminum alloys

Using the nondestructive testing techniques conductivity measurement and ultrasonic testing, we explored the importance of the effect of Mg content (3–6 wt%) on the corrosion and mechanical properties of 5000 series chill-rolled Al–Mg alloys. The results indicate that all of alloys showed no β-phase precipitation before sensitization and that their conductivity and sound wave velocity decreased with increasing Mg content. After sensitization of the alloys, their grain boundaries showed significant β-phase precipitation and corrosion. The alloy conductivity and sound wave velocity increased with the increase in Mg content. Precipitates became more obvious and continuous, and the change in rate of conductivity was greater, while the change in rate of sound wave velocity had a less-significant trend.Addition of Mg atoms not only increased the strengthening effect on the solid solution of Al–Mg alloys, but it also reduced the stacking-fault energy of the alloys. During tensile deformation, the alloys exhibited high work-hardening rate, effectively suppressing the occurrence of necking. Thus, when the Mg content was higher, the strength and elongation of the alloy increased. In contrast, the strength of sensitized high-Mg alloys declined within a larger range. The conductivity, sound wave velocity, corrosion properties, and mechanical properties were linearly correlated. We thus demonstrated that nondestructive testing techniques can be effective methods for evaluating the effect of Mg content on the corrosion and mechanical properties of chill-rolled Al–Mg alloys. Moreover, the conductivity measurement was more sensitive than was ultrasonic testing in detecting precipitation of the strengthening phase.

Crystallography and reorientation mechanism upon deformation in the martensite of an α-α’ Ti-6Al-4V dual-phase microstructure exhibiting high work-hardening rate

The present study provides a fundamental understanding of the crystallography and the microscale behavior of the V-enriched and Al-depleted α’ martensite taking place during the microstructure formation and the deformation of the dual phase α + α’ microstructure produced in Ti-6Al-4V. This particular microstructure exhibits much larger work-hardening capabilities than the conventional wrought product. The as-quenched structure of the martensite is analyzed using the Phenomenological Theory of the Martensite Crystallography (PTMC) coupled with EBSD analyses. This approach sheds new light on the microstructure configuration obtained during the dual-phase treatment and its fine-scale mechanical behavior. The martensite preferentially forms into parallel groups of 3 self-accommodating variants separated by a misorientation of 63.26∘/[10¯553¯]α’. TEM analyses additionally show that the variants of a same group are separated by a hitherto unobserved {134¯1}α’ type twin plane. Postmortem analyses after tensile testing demonstrate that this twinning plane is mobile under deformation. This allows the martensitic microstructure to exhibit the remarkable property to reorient under uniaxial tension. This unique property is shown to be intimately related to the mobility of the {134¯1}α’ twinning plane thereby evidencing for the first time that twin boundary motion is not uniquely associated to the orthorhombic α’’ martensite but can also occur in hexagonal α’ martensite. Quantification of the Interaction Energy (IE) appears relevant to rationalize and predict the reorientation of the martensite. The critical influence of the parent β grains texture on the reorientation is evidenced, while the impact of this deformation mechanism on the ductility of the martensite is debated.