Early Stages Of Plastic Deformation Research Articles

Heterogeneous Multi-Phase Grains Improving the Strength-Ductility Balance in Warm-Rolled Fe-18Mn-3Ti Steel

The thermal properties, microstructure, and mechanical properties of Fe-18Mn-3Ti (wt%) were investigated, focusing on the effects of different heat-treatment processes. Results revealed that the 450 °C warm-rolling sample (450 WR) exhibited promising mechanical properties. Specifically, this sample displayed a yield strength of 988 MPa, an ultimate tensile strength of 1052 MPa, and total elongation of 15.49%. Consequently, a favorable strength-ductility balance was achieved. The strain-hardening ability surpassed that of the cold rolling sample (CR). Microstructure analysis indicated the simultaneous occurrence of dynamic equilibrium between grain deformation and re-crystallization because of the co-influence of thermal and strain in the warm rolling process. This desirable mechanical property was attributed to the presence of a multi-phase (α-martensite, austenite, and ε-martensite) and heterogeneous microstructure. The improvement of ultimate tensile strength was based on grain refinement, grain co-deformation, and the transformation-induced plasticity (TRIP) effect in the early stage of plastic deformation (stage Ⅰ). The improvement of ultimate elongation (TEL) was ascribed to the TRIP effect in the middle stage of plastic deformation (stage Ⅱ).

Formation of intracrystalline deformation twins in austenitic Mn-steel at the early stage of plastic deformation

In austenitic Mn-steels with low stacking fault energy, the deformation twin is known to play an important role in plastic deformation. Usually, the position grain boundary is preferred to observe and investigate the formation process of the deformation twin, while other suitable formation positions may be neglected. Here, high-resolution transmission electron microscopy is used to observe and characterize the formation of intracrystalline twins in 120Mn13 steel at the early stage of tensile plastic deformation at the atomic scale. The result shows that intracrystalline twins nucleate through overlapping stacking faults generated by three different perfect dislocations dissociating on consecutive {111}-type planes, which is different from twin nucleation mechanisms that have been proposed. Subsequently, they become large-sized intracrystalline twins or twin bands throughout the whole grain by twin nuclei growing themselves and connecting to adjacent twin nuclei or existing twins in the same growth direction. Intracrystalline twins are mainly formed in three positions, namely near the grain boundary, at the end or side of existing twins. The stacking fault sources of intracrystalline twins at different positions are different.

Tailoring nanoprecipitates to achieve ultrahigh strength (CoCrNi)94.5W3Ta2.5 medium-entropy alloys

Metallic materials with high mechanical performance are in constant demand by various engineering applications. However, most conventional strengthening mechanisms inevitably suffer from fiercely sacrificing ductility, which severely limits service safety of metallic alloys, especially under various harsh circumstances. In this work, a novel ultra-strong (CoCrNi)94.5W3Ta2.5 medium entropy alloy (MEA) with dual nanoprecipitates is successfully developed. By conducting multiple thermomechanical processes, not only quantities of coherent γ" nanoprecipitates with D022 superlattice are introduced, but also massive semi-coherent η nanoprecipitates with hexagonal D024 superlattice are reconstructed with appropriate sizes and distributions, meanwhile ultrafine grains are achieved, together enabling superior strength-ductility synergies. This MEA exhibits not only high tensile strength of about 1.7 GPa and ultimate elongation of 23.8 % at room temperature, but also ultra-high tensile strength of about 2.2 GPa and still sufficient ultimate elongation of 13.2 % at cryogenic temperature. In-depth microstructure characterization indicates that the nanoprecipitates are effective barriers to dislocation motion at the early stages of plastic deformation. Intriguingly, the slip and deformation twinning could be transmitted across the phase boundaries with increasing applied strain, ensuring both strength enhancement and plasticity maintenance. At cryogenic temperature, much more complex deformation mechanisms are activated, e.g., multiple slip systems and high-density deformation twins, facilitating even better mechanical properties. The design concept of strengthening materials via tailoring dual coherent nanoprecipitates may afford a paradigm to develop advanced metallic materials with ultrahigh strength.

An order of magnitude enhancement in ductility of a metallic glass of peak rejuvenation

Exceptional ductility has been a long-sought-after property of metallic glasses, and cryogenic thermal cycling rejuvenation has been actively explored to enhance the plasticity of metallic glasses. By tuning the holding time and number of cycles of cryogenic thermal cycling processing, we here report a (Zr0.8125Cu0.1875)79Ni10Al10Nb1 metallic glass of peak rejuvenation with the plasticity of an order of magnitude higher than that of the as-cast glass, without sacrificing its strength. Characterizations indicate that the loose atomic packing of the metallic glass of peak rejuvenation facilitates the generation and proliferation of shear bands in the early stage of plastic deformation, and the resultant dense shear bands tend to be deflected due to their interaction with each other and/or structural inhomogeneity in the matrix, hindering their rapid propagation and in turn increasing the plasticity. The combination of high relaxation enthalpy and high plasticity obtained here is outstanding from the previous rejuvenated metallic glasses which have either high relaxation enthalpy or high plasticity, while never both. This work identifies an alloy system with very high efficiency in plasticity improvement through cryogenic thermal cycling rejuvenation and represents a promising guide for improving the plasticity of metallic glasses.

Achieving excellent strength and ductility synergy by δ phase strengthening in low-density high-manganese steel

ABSTRACT In this study, we developed a novel lightweight Fe-Mn-Al dual-phase with high strength, excellent ductility, and considerable toughness. The study involved a thorough exploration of heat treatment processes and mechanical behaviour. The microstructure of the Fe-Mn-Al dual-phase steel consists of austenite and δ-ferrite. In the early stages of plastic deformation, austenite undergoes primary deformation, leading to a faster increase in dislocation density and microhardness. In later stages, strain is transferred from austenite to δ-ferrite through high-density dislocation walls, resulting in coordinated deformation of the two-phase structure. The excellent strength-ductility combination of Fe-Mn-Al dual-phase steel is attributed to multiple stages of continuous work hardening. Initially, dislocation nodes in δ-ferrite contribute to work hardening. Subsequently, high-density dislocation structures and the strengthening effect of hard δ-ferrite enhance work hardening. Finally, deformation twins in austenite, along with the TWIP effect, further increase work hardening, emphasizing the importance of these interactions in improving mechanical performance.

Effect of compression bonding temperature on the strength-ductility balance of AA7075 alloy

In this study, the effect of compression bonding temperature on the microstructure and strength-ductility balance of AA7075 alloy was investigated. The results showed that dynamic recovery (DRV) was the dominant restoration mechanism in the compressed samples at 25, 100, 200, and 300 °C decreasing the dislocation density of elongated grains, while dynamic recrystallization (DRX) was predominant in the compressed sample at 400 °C forming fine equiaxed grains. By increasing the compression temperature, the bonding quality is improved. Several MgZn2 peaks could be observed in the diffraction pattern of the processed sample at 400 °C, confirming the occurrence of overaging. By increasing the compression temperature from 25 °C to 300 °C, the texture parameter of {200} (as recrystallization texture) was continuously reduced from 2.13 to 1.11, while the texture parameter of {220} (as deformation texture) was continuously enhanced from 2.09 to 4.91 due to the higher height reduction in the larger compression temperature. By further increasing the compression temperature to 400 °C, the texture parameter of {200} is significantly increased from 1.11 to 3.21, while the texture parameter of {220} is remarkably decreased from 4.91 to 0.83 owing to the occurrence of DRX. By increasing the temperature from 25 °C to 400 °C, the hardness of both AA7075 and pure aluminum layers was decreased due to the intensifying recovery and recrystallization. After the compression bonding, no evidence of the Portevin Le Chatelier was found and the stress-strain curves exhibited normal behavior. With increasing the temperature from 25 °C to 400 °C, yield and ultimate tensile strength were decreased from 672.7 MPa and 689.8 MPa to 187.4 MPa and 374.9 MPa, respectively, while the total elongation and energy absorption were increased from 6.2% to 40.6 J/cm3 to 33.7% and 108.1 J/cm3, respectively. At the early stage of plastic deformation, the strain hardening rate of the compressed sample at 400 °C was significantly lower than that of other compressed samples. However, when the ε reaches 0.09, the strain hardening rate of the sample became larger than that of other processed samples due to the recovery of the strain hardening rate (RSHR) phenomenon at stage III in the compressed sample at 400 °C. The fracture features of all samples were characterized by dimples and cleavage facets, indicating the occurrence of a mixed ductile/brittle mode of fracture. However, by increasing the compression temperature, the dimpled portion of the fracture surface was increased. The dimples were coarsened when the compression temperature increased owing to the softening of samples as well as coarsening of MgZn2 precipitates at higher temperatures.

Achieving ultrahigh strength and ductility in high-entropy alloys via dual precipitation

The strength-ductility trade-off has been a longstanding dilemma in metallic materials. Here we report an innovative approach to achieve a high strength-ductility synergy via dual precipitation of sheared and bypassed precipitates. (Ni2Co2FeCr)96–xAl4Nbx (at.%) alloys strengthened by nanoscale L12 particles and Laves precipitates were selected as a model for this study, and their precipitate microstructures and mechanical properties were thoroughly investigated. The dual-precipitation-strengthened alloys exhibit a yield strength of more than 1400 MPa, an ultimate tensile strength of over 1800 MPa, and a uniform elongation of 18%, thus achieving a high strength-ductility synergy. Our analysis reveals that the nanoscale L12 precipitates contribute to the strength via the particle shearing mechanism, whereas the Laves phase provides the strengthening through the Orowan bypass mechanism. The study of deformation microstructures shows that the L12 precipitates are sheared by stacking faults, which facilitates long-range dislocation gliding through the matrix. As a result, deformation induces the formation of hierarchical stacking fault networks and immobile Lomer–Cottrell locks, which effectively enhance the work hardening capability and plastic stability, thereby resulting in a high ductility at high strength levels. Dislocations are piled-up against the interface between the Laves precipitates and matrix, which increases the work hardening capability at the early stages of plastic deformation but causes stress concentrations. The dual precipitation strategy may be useful for many other alloys for achieving superior mechanical properties for technological applications.

An investigation of slip transmission during uniaxial tensile deformation of a coarse-grained copper via EBSD characterization and crystal plasticity modelling

This study explores the phenomenon of slip transmission across grain boundaries in coarse-grained copper. The associated effects on the deformation gradient are also investigated, using both experiment and simulation. An in-situ tensile test of a fully annealed copper specimen was conducted first using a scanning electron microscope (SEM). The deformation gradient and geometrically necessary dislocation (GND) maps at selected tensile strain values were obtained and characterized by electron backscatter diffraction (EBSD). In addition, a physically based strain gradient crystal plasticity finite element method model has been developed to simulate the early stage of tensile deformation behaviour of copper. In this model, slip transmission across the grain boundary is either allowed or blocked, depending on the alignment of adjacent grains. Slip transmission is allowed at grain boundaries between suitably aligned grains according to the Luster-Morris factor, residual Burgers vector is applied to consider the slip misalignment at GB region, and dislocation accumulation at grain boundaries is included following the Kocks-Mecking law. It was found that dislocation pile-up, lattice rotation and stress concentration were much higher near the impenetrable grain boundaries than at the penetrable ones. Due to the slip transmissions across grain boundaries, the stress and strain concentrations can be partially relaxed, and the slip transmission induced relaxation is associated with the number of active slip systems and shear strain on the best aligned slip systems. This study provides an effective strategy to investigate the early stage of plastic deformation, and a good agreement between experimental observations and simulation results has been achieved.

Strain Rate-Dependent Anomalous Work Hardening of a Single-Crystalline CoNi-Base Superalloy

The deformation mechanisms operating in superalloys depend on different parameters such as composition, temperature and deformation rate. So far, the transition from shearing by APB-coupled dislocations to shearing under the formation of stacking faults has been studied exclusively as a function of temperature but not as a function of the strain rate. Therefore, interrupted compression tests with strain rates between 10–3 s−1 and 10–5 s−1 were performed on the single-crystalline CoNi-base superalloy ERBOCo-4 at a temperature of 850 °C. The evolution of the defect structures has been analyzed by conventional transmission electron microscopy. A change of the deformation mechanism from APB-coupled dislocation shearing to stacking fault shearing is found to depend on the strain rate. At lower strain rates, an increased stacking fault density is associated with a higher yield strength and higher work hardening rates at the early stages of plastic deformation due to a very high stacking fault density. After approximately 2.0 pct plastic strain, the stress reaches a plateau and decreases subsequently, which is associated with the formation and thickening of twins as shown by high-resolution scanning transmission electron microscopy. At higher strain rates, the work hardening rate is significantly lower in the early deformation stage. The role of segregation to planar defects and the influence of local phase transformations (LPT) at SESFs is further discussed in reference to the influence of the strain rate. The segregation of W as an η stabilizing element is found to be crucial for the formation of a local phase transformation in ERBOCo-4. At higher strain rates the phase transformation is hindered by insufficient W segregation, resulting in a higher twin density.

Investigations on the tensile deformation of pure Mg and Mg–15Gd alloy by in-situ X-ray synchrotron radiation and visco-plastic self-consistent modeling

In this study, the texture evolutions of two Mg materials during tension are explored. In-situ X-ray synchrotron and Visco-Plastic Self-Consistent (VPSC) modeling are employed to investigate the different deformation modes between pure Mg and Mg–15Gd (wt.%) alloy. These two materials with a strong extrusion texture show large different slip/twinning activity behaviors during tensile deformation. The basal 〈a〉 slip has the highest contribution to the initial stage of plastic deformation for pure Mg. During the subsequent plastic deformation, the prismatic slip is dominant due to the strong ED // 〈100〉 fiber texture. In contrast, the deformation behavior of Mg–15Gd alloy is more complex. Twinning and basal slip are dominant at the early stage of plastic deformation, but further deformation results in the increased activation of prismatic and pyramidal slips. In comparison to pure Mg, the ratios of the critical resolved shear stress (CRSS) between non-basal slip and basal slip of the Mg–15Gd alloy are much lower.

Formation condition and effect on the early stages of plastic deformation of chemical short-range order in Cr-Co-Ni medium-entropy alloy

The variation in the chemical short-range order (CSRO) of Cr-Co-Ni medium entropy alloy is investigated by measuring the electrical resistivity at various temperatures. According to the measurements at various cooling rates, the thermodynamic equilibrium at temperatures higher than 1075 K cannot be quenched in most conventional sample preparations. The resistivity quenched at various temperatures increases with decrease in annealing temperature, especially below 873 K. The activation energy of the reaction is determined 240–270 kJ mol−1. The activation energy is almost the same as that of atomic diffusion in the Cr-Mn-Fe-Co-Ni high-entropy alloy, indicating that the electrical resistivity change is associated with the change in the atomic arrangement. Using the results of electrical resistivity measurements, the effect of the degree of CSRO on the early stage of plastic deformation was investigated by compression tests on single crystals with varying degrees of CSRO. The critical resolved shear stress and activation volume of the slip are found to be virtually independent of the degree of CSRO. Repetitive strain-rate jump tests indicates that the degree of CSRO does not significantly affect the dislocation motion process in the early stages of the plastic deformation in Cr-Co-Ni medium entoropy alloy.

Effect of aging temperature on microstructure and mechanical properties of laser melted and hot isostatically pressed (CoCrFeMnNi)96(TiAl)4 alloy

In this study, a selectively laser melted (SLM) and hot isostatically pressed (HIPed) high entropy alloy (HEA), (CoCrFeMnNi)96(TiAl)4, was aged at different temperatures to investigate the microstructural evolution and mechanical property development with the aim of identifying the optimum aging condition that can produce the best combination of tensile properties for the alloy. It was found that the SLM-HIPed HEA contains a small density of nano-sized Al2O3 and σ particles. Upon aging at relatively low temperatures (650 °C and 700 °C), a high density of nano-sized long-range ordered (LRO) L12 domains formed from the matrix. Heusler and B2 particles also started to form from the matrix. With increased aging temperature, both the area fractions and sizes of Heusler, B2 and σ particles increased continuously. Aging at 750 °C gave rise to no LRO L12 domains but γ′ particles while aging at 800 °C led to disappearance of both LRO domains and γ′. The formation of Heusler and B2 precipitates was found to be associated with the diffusion of Al, Ti and Ni while that of σ is linked to the diffusion of Cr. Increased precipitation of Heusler and B2 with increased aging temperature was accompanied by the disappearance of LRO L12 domains, suggesting that the former may have competed with the latter in terms of absorption of Ni, Ti and Al. The samples containing LRO L12 domains and fine precipitates show the highest 0.2% yield strength (YS>610 MPa) and ultimate tensile strength (UTS>960 MPa) while maintaining a high elongation (EL>25%). Those that are free of LRO L12 domains and contain large Heusler, B2 and σ particles show much lower YS (∼490 MPa) and UTS (760–850 MPa) as well as reduced ductility. The results indicate that the formation of LRO L12 domains is crucial for acquisition of enhanced YS in the HEA. In the early stage of plastic deformation, paired dislocations were found to shear through the LRO L12 domains and with increased strains, a number of stacking faults formed with many of them intersecting with each other to form Lomer-Cottrell locks which favoured strain hardening. Dislocations tended to loop around Al2O3, Heusler and σ precipitates, indicating that they can act as effective dislocation motion obstacles.

Composition design of a novel Ti-6Mo-3.5Cr-1Zr alloy with high-strength and ultrahigh-ductility

• A novel titanium alloy with high strength and ultrahigh ductility was designed to break through the longstanding strength-ductility trade-off. • The strong strain partitioning effect and the dislocation pile-up effect caused by SIω were found and quantitatively analyzed by in situ EBSD/DIC and in situ TEM tests, respectively. • The TRIP/TWIP/DPU coupling effect during plastic deformation was firstly proposed and deciphered. The strength-elongation to fracture ( ε f ) trade-off and low strain hardening rate have been a longstanding dilemma in titanium alloys. In this work, we innovatively manufactured a novel Ti-6Mo-3.5Cr-1Zr alloy via the introduction of a stress-induced strengthening phase into the material. Stress-induced ω (SI ω ) phase transformation was expected to replace the α'' martensitic transformation that resulted in the low yield strength of titanium alloys. The obtained alloy exhibited an extremely high strain hardening rate of up to ∼1820 MPa. The true peak tensile strength and ε f reached ∼1242 MPa and ∼40%, respectively. The intrinsic mechanisms underlying the simultaneous improvement of strength and ductility of the material were systematically investigated via in-situ and ex-situ characterizations. In-situ electron backscatter diffraction (EBSD)/digital image correlation (DIC) results showed that SI ω phase transformation dominated the early stage of plastic deformation (1.5%–3%) and promoted the strain partitioning between the stress-induced bands and β matrix. Subsequently, the formation of {332}<113> β twins and ω twins was observed via ex-situ EBSD. In-situ transmission electron microscopy results revealed that dislocation pile-up (DPU) occurred at the SI ω / β interface. The coupling effects associated with the transformation induced plasticity (TRIP), twinning induced plasticity (TWIP), and DPU mechanisms contributed to the enhanced strength and ε f of the designed titanium alloy.

Additional dislocation slip determined excess yield stress in titanium

The excess yield stress induced slip system variations at the early stage of plastic deformation in Ti was in-depth studied. As a common sense, both the normal grain refinement according to the Hall-Petch relationship and the suppressed dislocation source activation in refined-grain can extensively increase the yield stress. In this study, combined calculations of Schmid factor and critical resolved shear stress suggest that small-grain samples with much higher yield stress could incorporate both <a>-prismatic slip and <c+a>-pyramidal slip, while only <a>-prismatic slip can be activated in the large-grain counterparts. This slip system transition can explain the abnormal fine-grain strengthening effect, which the experimental yield stress of small-grain sample deviates from the value that predicted by using Hall-Petch relationship, as well as the stress drop right after yielding in Ti. These findings could also provide a new strategy for designing high-strength metallic materials.

Mechanics of accelerated strain hardening in harmonic-structure materials

Harmonic-structure (HS) design is one of the most efficient in the family of architected gradient-structure materials recently attracting increasing attention in global material science community due to leading structural performance characteristics. This work studies in situ the mechanics of plastic deformation in HS materials on the example of commercially pure nickel (Ni) during uniaxial tensile loading. It reveals that strain partitioning between ultrafine and coarse grain fractions in HS Ni commences already at early stages of plastic deformation. Slow accumulation of strain in the ultrafine-grain regions leads to the slow consumption of ductility resource, while accelerated accumulation of strain in the coarse-grain regions leads to an accelerated strain hardening. These effects combined with evolving variations of strain tensor components have synergetic effect leading to the unique plastic behaviour and excellent structural performance of HS materials.

In situ synchrotron tensile investigations on ultrasonic additive manufactured (UAM) zirconium

The microstructure evolution during room temperature uniaxial tensile straining of ultrasonic additive manufactured (UAM) zirconium was evaluated using the Advanced Photon Source (APS) facility. Miniature dog-bone tensile specimens of two orientations were cut from a UAM-fabricated zirconium bar for in situ synchrotron tensile tests. Wide-angle X-ray scattering (WAXS) scanning was used to unveil the changes in microstructure of the entire gauge regions throughout the straining. A series of WAXS data analysis methods were utilized to quantify both elastic and plastic deformation mechanisms within the strained specimens. Stress concentrations were identified during early stages of plastic deformation, which become candidate necking positions and eventually lead to failure. Fracture surface analysis implied that these stress concentration locations may be correlated to the fabrication defects, providing insightful guidance for future improvements of the UAM zirconium fabrication process.

Negative strain rate sensitivity of yield strength of Al-Si alloy additive-manufactured using laser powder bed fusion

This article reports an unexpected finding of the mechanical behavior of Al-12%Si alloy manufactured using the laser powder bed fusion (L-PBF) process. The as-manufactured specimen has a negative strain rate sensitivity of flow stress at an early stage of tensile deformation (below 3% in strain). The post heat-treated specimens exhibited a positive strain-rate sensitivity and none of these specimens exhibited a serrated stress-strain curve, indicating a mechanism different from the Portevin–LeChatelier effect. Transmission electron microscopy revealed the dynamic precipitation of the nano-sized Si-phase inside the supersaturated solid solution of the α-Al matrix in the as-manufactured specimen deformed at ambient temperatures. The dynamically precipitated Si phase interacted with the introduced dislocations, enhancing the flow stress during the early stages of plastic deformation. The dynamic precipitation could contribute to the negative strain-rate sensitivity of the flow stress at an early stage of tensile deformation (including the yield strength).

Multiple minor elements improve strength-ductility synergy of a high-entropy alloy

The developments of multicomponent high-entropy alloys usually put emphasis upon the roles of multiple principal elements in optimizing the various properties. Instead of tuning the principal elements, here we propose to use multiple minor alloying elements to improve performance of HEAs. To this end, the microstructure and mechanical behavior of a newly developed alloy, i.e., Fe35Ni20Co20Cr20Al2.5Ti1.0Cu1.0Si0.5 (at. %), have been investigated. The alloy decorated by the multiple minor alloying elements (i.e., Al, Ti, Cu and Si) exhibits a single face-centered cubic (FCC) γ phase in fully recrystallized state. Compared with the undecorated Fe40Ni20Co20Cr20 (at. %) counterpart with similar grain size, the yield strength of the decorated alloy sample with multiple minor elements is enhanced by ∼19% at a high elongation of ∼74%. Microstructural characterizations indicate that dislocation slip prevails at the early stages of plastic deformation while mechanical twins are observed to occur at the late deformation stage. The local stress field caused by the atomic size mismatch and elastic mismatch originated from the multiple minor elements significantly impedes the movement of dislocations thus improves the strength. Such retarding effect of the multiple minor elements on mobile dislocation further hinders the generation of stacking faults on adjacent atomic planes and thereby increases the FCC-γ phase stability, which also postpones the deformation twinning upon tension. This work demonstrates the practical significance of introducing multiple minor alloying elements with their synergistic effect into HEAs, and the design strategy enlarges the space for compositional design of advanced alloys.

Effect of deformation-induced martensitic transformation on nonuniform deformation of metastable austenitic steel

A digital image correlation technique combined with in situ neutron diffraction was used for the first time to investigate the Portevin–Le–Chatelier (PLC) behavior in an Fe–24Ni–0.3C steel. Propagating type A + B PLC bands observed in the early stage of plastic deformation changed to the non-propagating type C bands due to the occurrence of deformation-induced martensitic transformation.

Suppression and reactivation of transformation and twinning induced plasticity in laser powder bed fusion additively manufactured Ti-10V-2Fe-3Al

Laser powder bed fusion (LBPF) was employed to fabricate a strain-transformable β-Ti alloy, Ti-10V-2Fe-3Al (wt%). While the alloy is known to exhibit transformation induced plasticity (TRIP), the as-fabricated alloy, under tensile loading, did not show the same TRIP effects, even though it exhibits the same β + ω microstructure. The repeated heating-cooling cycles experienced during the LBPF process leads to the early stages of rejection of solute elements (Fe, V, and Al), forming isothermal omega (ω) precipitates, which were captured via detailed investigations coupling transmission electron microscopy (TEM) and three-dimensional atom probe tomography (APT). While these homogeneously distributed isothermal ω precipitates lead to a higher yield strength, the TRIP/TWIP effects within the β matrix were suppressed, leading to very low ductility and virtually no strain-hardenability. Interestingly, after a simple β-solution heat treatment followed by quenching, leading to a β + ω (athermal) microstructure, the TRIP/TWIP effects were reactivated in the same LPBF Ti-10 V-2Fe-3Al alloy. The alloy exhibited substantial recovery of tensile ductility and a very large strain hardening (tensile strength minus yield strength ~500 MPa), with a high average strain hardening rate ~15000. Such a very high strain hardening rate in case of LBPF processed Ti-10 V-2Fe-3Al, appears to arise from a rapid strain-induced transformation from β to α" at the early stages of plastic deformation, leading to a high-volume fraction of the martensitic phase, coupled with hierarchical twinning within the martensite plates.