Face-centered Cubic Research Articles

Determination of MAX phase structure and surface reconstruction behavior of a novel V–Sn–C system

The crystal structure of a novel MAX phase is determined using X-ray powder diffraction, spherical aberration corrected transmission electron microscopy, and first-principles calculations. In the new V–Sn–C system, the R 3‾ m space group aligns more closely with the experimental data than the P63/mmc space group. The lattice parameters of the new trigonal V2SnC phase are a = 0.291 nm and c = 2.08 nm. Moreover, the surface of the new phase has a tin-doped carbide face-centered cubic (FCC) structure reconstruction layer. First-principles calculations indicate that the new trigonal V2SnC phase is metastable compared with the hexagonal V2SnC phase. However, the thermal stability of the metastable trigonal V2SnC in air is significantly enhanced owing to the presence of the reconstruction layer.

Interstitial engineering enabling superior mechanical properties of nitrogen-supersaturated Fe50Mn30Co10Cr10 high-entropy alloys

Interstitial atoms are key in modifying microstructures and enhancing mechanical properties of metals. Traditionally, the introduction of interstitial elements into metal matrices has been limited to low levels (< 2 at.%) to avoid the formation of brittle ceramics, constraining the exploitation of their full strengthening potential. This study introduces nitrogen-supersaturated high-entropy alloys (HEAs) with up to 28.9 at.% nitrogen, achieving substantial interstitial strengthening and phase adjustment. Remarkably, these HEAs remain solid solution phases without nitride formation, even at exceptionally high nitrogen levels. The microstructural evolution with increasing nitrogen content transitions from a single face-centred cubic (FCC) structure to a dual-phase structure of FCC and hexagonal close-packed (HCP) phases, and ultimately reverts to a predominantly FCC structure. These alloys achieve an impressive hardness of ∼ 20 GPa, comparable to ceramics, while maintaining exceptional damage-tolerance and plasticity. The outstanding mechanical properties are attributed to massive solid solution strengthening from a high nitrogen level, a hierarchical dual-phase structure, and stress-induced phase transformation from FCC to HCP. Contrary to the brittleness typical of nitrides, these nitrogen-supersaturated HEAs exhibit substantial plastic deformation akin to metallic materials, thus opening up a new pathway for enhancing the mechanical performance of advanced alloys under extreme loading conditions.

Evaluating load-bearing and hypervelocity impact shielding capabilities of face-centered cubic lattice core sandwich panels

In the present paper, a comparative study on load-bearing as well as hypervelocity impact shielding performance of sandwich panels with face-centered cubic (FCC) lattice core is numerically performed in order to evaluate their competency in satellite structure applications. To this end, 5A06 aluminum alloy FCC and FCCz beside cube and octahedron lattice structures with similar areal densities were investigated. Whipple shield structure of same material and areal density was also studied in order to be compared to lattice structure in protection field. The present study simulates hypervelocity impact of a spherical projectile with 2 mm diameter, represents the space debris, collides with the structures at the velocity range of 2–6 km/s. Numerical simulation model was validated by performed experimental study. Authors were inspired by cube and FCCz topologies to propose a novel lattice structure could provide outstanding shielding and load-bearing capabilities in comparison to the other structures studied in this research. Furthermore, the detailed effects of projectile impact location on the protection performance were investigated and the mentioned item was found to have considerable influence on the structure shielding performance.

Critical impacts of thermodynamic instability and short-range order on deformation mechanisms of VCoNi medium-entropy alloy

Short-range order (SRO) has made a splash in the recent research on multi-principal element alloys (MPEAs), among which the equiatomic VCoNi alloy was regarded as the most potential prototype. However, in addition to disputes over SRO, there is still a lack of agreements on the phase stability and deformation mechanism of the VCoNi alloy, which should be addressed before the SRO can be independently analyzed. To this end, microstructural evolutions with increasing long-term annealing temperatures (from 700 to 1,200 °C) were first inspected in detail to determine critical temperatures for phase transitions unambiguously. Our results revealed that the VCoNi alloy was still dominated by the face-centered-cubic (FCC) structure with a minor κ phase at 900 °C and became a single FCC solid solution at above 910 °C. Subsequently, by carefully examining dislocation configurations and stacking fault (SF) widths in the FCC phases annealed at 900 °C and 1,200 °C, significant variations in local stacking fault energy (SFE) were unveiled, and the overall SFE decreased with increasing annealing temperature. Combined with the state-of-the-art density function theory (DFT)-based lattice Monte Carlo (MC) simulation, we demonstrated how the rise/decline in SFE can be explained by the greater/lower degree of SRO. This research would not only offer new perspectives for recent controversies over phase stability, deformation mechanism, and SRO characterization technique using electron diffraction but also shed light on the intrinsic relationship between SRO and local stacking fault energy of MPEAs.

Kinetics and mechanisms of high-temperature oxidation in BCC and FCC high-alloy Fe-based alloys with high volume fraction of carbides

This study conducts a detailed analysis of high-temperature oxidation and microstructural evolution in two high-alloy Fe-based alloys, each characterized by a high-volume fraction of carbides but differentiated by their matrices − body-centered cubic (BCC) and face-centered cubic (FCC), which was achieved by the addition of nickel. By investigating the intricate interplay of factors such as phase composition, nickel content, and the presence of carbides, this research aims to elucidate the diverse oxidation kinetics and underlying mechanisms specific to each alloy type. Results show that the BCC alloy exhibits slower oxidation kinetics compared to its FCC counterpart, suggesting better performance in high-temperature environments. Moreover, while both alloys develop strong adhesive oxide scales primarily composed of Cr2O3, the FCC alloy experiences more pronounced scale spallation and cracking. A faster progression of decarburization was observed in the BCC alloy. This comprehensive comparison highlights how variations in matrix structure, along with nickel content and carbide behavior, critically influence oxidation kinetics, scale adhesion, and the overall integrity of oxide scales. Understanding these nuanced interactions is crucial for designing high-performance alloys tailored for extreme operating conditions.

Minor element doping effects on microstructure and mechanical properties of a non-equiatomic FeNiCoCr high-entropy alloy

Through the addition of minor alloying elements, we have designed and prepared a new non-equiatomic six-membered Fe41Ni20Co20Cr10Al5V4 (at. %) high-entropy alloys (HEAs), with the aim of further improving HEA performance. The effect of annealing temperature on HEA microstructure and mechanical properties was systematically studied by using a variety of characterization methods. The results show that HEA Fe41Ni20Co20Cr10Al5V4 is a single-phase face-centered cubic (FCC) solid solution structure. The yield strength HEA Fe41Ni20Co20Cr10Al5V4 doped with minor element doped is 15% higher than that of the base alloy Fe40Ni20Co20Cr20 with a similar grain size while retaining good plasticity (elongation >50%). This can be attributed to the increased lattice distortion induced by the doping elements (i.e., Al and V). In addition, the strengthening mechanisms of Fe41Ni20Co20Cr10Al5V4 HEAs were analyzed. HEA strengthening mechanisms mainly include solid-solution strengthening, grain-boundary strengthening, and dislocation strengthening. Among them, in partially recrystallized HEA, fine-sized dislocation cells formed by the intertwining of high-density dislocations significantly increase material strength. Due to the excellent plasticity (∼ 61%) inherent in HEA as-homogenized, further research can be carried to improve its strength with minimal compromise to plasticity in order to achieve a better balance between strength and ductility.

Carbohydrate-based block copolymers with sub-10 nm face-centered cubic nanostructures for low-power-consuming and ultraviolet light-triggered synaptic phototransistors

Addressing environmental concerns and producing sustainable and environmentally friendly electronic devices with low power consumption poses a significant challenge. This study introduces phototransistor devices employing morphologically controlled block copolymers based on maltotriose, maltoheptaose, and β-cyclodextrin as polymer electrets. Ordered self-assembled morphologies can be achieved by utilizing microwave radiation for rapid annealing (within 5 s) with optimized annealing conditions. Herein, face-centered cubic (FCC), vertical, and mixed cylindrical nanostructures are reported. The resulting well-defined morphologies play a pivotal role in enhancing the electron-trapping capability of the block copolymers and facilitating charge carrier transport between the electret and semiconducting layers. Consequently, the phototransistor memory manifests exceptional performance, featuring stability and endurance. Intriguingly, the cavity of β-cyclodextrin provides a stable environment for the trapped charges, leading to a larger memory window than other block copolymers. On the other hand, a device consisting of MT-b-PS exhibited superior current contrast exceeding 106 even under a low drain voltage of −1 V, attributed to sub-10 nm FCC nanostructures. Furthermore, this phototransistor device successfully emulated the synaptic functions of sensing, learning, and short- and long-term memory in the human brain, along with a low energy consumption of 0.312 fJ. Hence, this report opens the pathways for developing promising bio-based electronic devices.

A novel high-entropy alloy with excellent mechanical properties, corrosion resistance, and antibacterial properties

Microbiologically influenced corrosion is a challenge problem involving many fields and causes great corrosion losses. Developing antibacterial structural materials is one of the effective strategies to solve above issues. The current study reports a novel Al0.2CoCrFeNiCu0.3Ta0.1 HEA with outstanding mechanical properties, corrosion resistance, and antibacterial properties. The HEA exhibited a face-centered cubic (FCC) structure with L12 nanoprecipitates enriched in Al–Ni–Ta–Cu that are dispersed in the FCC matrix. Antibacterial rate of the HEA against Bacillus subtilis was more than 99.99 %, which was far superior to that of the traditional antibacterial Cu-bearing 304 stainless steel (72.84 %). The ultimate tensile strength and yield strength of the HEA were 1053.5 MPa and 602.5 MPa, respectively, which were much higher than those of traditional antibacterial Cu-bearing 304 stainless steel (530.5 MPa and 242.8 MPa, respectively) without apparent loss of ductility. In addition, this HEA displayed an excellent corrosion resistance that was superior to that of 304 stainless steel and antibacterial Cu-bearing 304 stainless steel.

Analysis on heat transfer and flow performance of pebble-bed fuel in three regular arrangements with multi-layers

The fuel pebbles in the core of the high-temperature reactor (HTR) are randomly arranged, making it difficult to analyze the heat transfer and flow characteristics quantitatively. Traditionally, three regular fuel pebble arrangements—simple cubic (SC), body-centered cubic (BCC), and face-centered cubic (FCC)—have been used in quantitative studies to determine the possible HTR heat transfer characteristics. However, most currently established arrangement models focus on a few layers, making them inadequate for revealing the variations in heat transfer and flow characteristics with different arrangements and pebble layers. This study established multilayered pebble-bed models for the three arrangements and analyzed the variations in the heat transfer coefficients with increased pebble layers. The reliability of the numerical computational approach was validated through a comparative analysis with experimental data. The study revealed that with the increase of layers, the heat transfer coefficient of SC and FCC arrangement basically stabled at 1480 and 4000 W/(m2·K). The heat transfer coefficient of BCC pronouncedly increased from 2500 to 3500 W/(m2·K). The flow velocity distribution suggested that the increase was caused by a rotation of the helium flow, which became apparent in the ninth layer and stabilized around the thirteenth layer. An analysis of the turbulent kinetic energy showed that this rotation was caused by an increase in turbulence. As the physical properties of helium changed, the flow became unstable and finally entered a new, stable state. Analysis of the boundary conditions at the inlet further supports this view.

Edge Dislocation and Grain Boundaries Effects on the Mechanical Properties in NiCoAl$N i C o A l$ Medium Entropy Alloy

Medium‐entropy alloys (MEAs) are becoming increasingly popular owing to their superior mechanical features. For the first time, using molecular dynamics (MD) simulations, investigation is done on how grain boundaries (GBs) and dislocations affect the mechanical properties of face‐centered cubic (FCC) equiatomic MEA. Lattice distortion, elastic constants and moduli, machinability index, Vickers hardness, and Kleinman parameters to explore how grain boundaries affect MEA are analyzed. It tends to become more rigid based on the link between its elastic moduli and GBs. Interestingly, the analyses of Cauchy pressure, Poisson's, and Pugh's ratios all indicate the ductility of the studied MEA. The investigation of anisotropy factors indicates that MEA exhibits anisotropy, which is reduced by the addition of GBs. Mechanical properties of the considered MEA, such as ductility, fracture toughness, and stability, are significantly influenced by the GBs. The obtained results show that studying these phenomena can help design structural nano‐metal materials with superior mechanical properties, allowing them to be used in various applications.

Analysis of the temperature-dependent plastic deformation of single crystals of quinary, quaternary and ternary equiatomic high- and medium-entropy alloys of the Cr-Mn-Fe-Co-Ni system

ABSTRACT Temperature-dependent plastic deformation behaviors of single crystals of quaternary and ternary equiatomic medium-entropy alloys (MEAs) belonging to the Cr-Mn-Fe-Co-Ni system were investigated in compression at temperatures in the range 9 K to 1373 K. Their critical resolved shear stresses (CRSSs) increase with decreasing temperature below room temperature. There is also a dulling of the temperature dependence of CRSS below 77 K due to dislocation inertial effects that we attribute to a decrease in the phonon drag coefficient. These behaviors were compared with those of previously investigated single crystals of the equiatomic Cr-Co-Ni and Cr-Fe-Co-Ni MEAs, and the equiatomic Cr-Mn-Fe-Co-Ni high-entropy alloy (HEA). The temperature dependence of CRSS and the apparent activation volumes below room temperature can be well described by conventional thermal activation theories of face-centered cubic (FCC) alloys. Above 673 K, there is a small increase in CRSS, which we believe is due to elastic interactions between solutes and mobile dislocations, the so-called Portevin-Le Chatelier (PL) effect. The CRSS at 0 K was obtained by extrapolation of fitted CRSS vs. temperature curves and compared with predictions from solid solution strengthening models of HEA and MEAs.

Strength Weakening and Phase Transition Mechanisms in Nanoindentation of Al/Mg-Layered Nanocomposites: A Molecular Dynamic Study

Molecular dynamics (MD) simulations were performed to investigate the nanoindentation behavior of Al/Mg-layered nanocomposites with varying layer thicknesses and Mg layer orientations in this study. The aim is to understand the weakening mechanisms at low layer thicknesses and the phase transition mechanisms associated with the dislocation slip angle in the Mg layer. Results indicate that the nanoindentation strength of nanocomposites increases with the layer thickness in the range of 1–10 nm, with the strength of 9.5 × 10−7 N at 10 nm being approximately 73% higher than that at 1 nm. This strength increase is mainly attributed to high interfacial stress, the higher percentage of amorphous atoms, weakened interatomic interactions, and the transition of adjacent interfaces to fully coherent interfaces that significantly reduce their ability to hinder dislocations at the low-layer thickness range. Additionally, in the initial deformation process, the hexagonal close-packed (HCP) phase of the Mg layer firstly transforms into the body-centered cubic (BCC) phase due to its lower energy barrier, followed by the emergence of a faced-centered cubic (FCC) phase driven by 1/3&lt;1−100&gt; dislocations. In the late stage of deformation, new dislocations are generated in the FCC phase and move along its slip planes, altering the dislocation direction. The FCC/HCP interfacial configuration also affects the HCP phase transition mechanism in the Mg layer. When the dislocation slip angle is 0°, the primary phase transition is the BCC phase, whereas a 45° slip angle results in the FCC phase. These findings will provide a guide for the preparation and manufacturing of new high-quality layered nanocomposites.

Effect of sintering temperature and doping content on phase evolution and microstructure of doped UO2 ceramics

ZrO2-doped UO2 ceramics have been considered as a promising high performance nuclear fuel in LWR due to its desirable properties. ZrO2-doped UO2 ceramic fuel samples with different contents of ZrO2 (20 wt%, 25 wt% and 30 wt% ZrO2, equivalent to 35.4 mol%, 42.3 mol% and 48.4 mol%, respectively) were prepared by pressureless sintering at various temperatures (1550 ℃, 1650 ℃ and 1750℃, respectively) for 4 h in a hydrogen reducing environment. Phase evolution and microstructure of as-sintered ZrO2-doped UO2 ceramic samples were investigated by X-ray diffractometer (XRD), scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS), respectively. Results show that there exists coexistence of uranium-rich U1-xZrxO2 phase with face-centered cubic (FCC) structure and zirconium-rich Zr1-yUyO2 phase with tetragonal structure in the 20 wt% ZrO2-doped UO2 ceramic sample when the sintering temperature is lower than 1650 ℃, while the UO2 and ZrO2 will form a single U1-xZrxO2 solid solution after sintering at 1750℃ for 4 h with the ZrO2-doped UO2 ceramic samples containing 25 or 30 wt% ZrO2, respectively. The significant differences of phase structure and ionic radius between ZrO2 and UO2 and the high atomic diffusion barrier are the main reasons that it is difficult to form a single solid solution for UO2-ZrO2 ceramic samples sintered at low temperature.

Regulation of mechanical properties in vanadium-containing high-nitrogen austenitic stainless steel via nano-Sized precipitated phase control

Nitride precipitation in high-nitrogen austenitic stainless steels significantly affects the mechanical properties of said steels. In this study, vanadium microalloying was employed to prepare high-nitrogen austenitic stainless steel with excellent comprehensive mechanical performance. The characteristics of the different precipitated phases, precipitation and dissolution behaviors, and their effects on mechanical properties were investigated. The impact mechanism of the precipitated phases on the mechanical properties of stainless steel was also discussed. The results indicate that the Me2X-type precipitated phase in the vanadium-containing high-nitrogen stainless steel exhibits a hexagonal close-packed (HCP) structure, forming a incoherent relationship with the matrix. This leads to a significant reduction in ductility owing to the larger size of particles enriched at the grain boundaries with minimal strengthening effects. Conversely, the MeX-type precipitated phase exhibits a face-centered cubic (FCC) structure, maintaining a semi-coherent relationship with the matrix. This results in smaller particle sizes and a more dispersed distribution, leading to a pronounced strengthening effect without compromising plasticity. Effective control of the precipitated phase can be achieved by solution treatment at different temperatures. Specifically, stainless steel subjected to a 1100 °C solution treatment exhibits only fine, dispersed MeX-type precipitated phases, resulting in optimal comprehensive mechanical properties: yield and ultimate tensile strengths of 587 and 924 MPa, respectively, with an elongation of 55% and a strength-ductility product of 49.6 GPa·%.

An excellent combination of strength and ductility via hierarchical precipitation structures in Co-free medium-entropy alloys

A Co-free non-equiatomic Ni2·5CrFeAl0·25Ti0.25 medium-entropy alloy (MEA) with an excellent strength-ductility synergy was fabricated, which shows a multiphase structure composed of face-centered cubic (FCC), L12 (ordered FCC), and Cr-rich body-centered cubic (BCC) phase by thermomechanical processing. Specifically, the aged sample displays the outstanding yield tensile strength (YTS, ∼1188 MPa), ultimate tensile strength (UTS, ∼1560 MPa) and work-hardening rate (WHR, ∼4.5 GPa) values as well as an acceptable plasticity of ∼16.6%. Theoretical calculations suggest that precipitation strengthening significantly contributes to achieving the fascinating tensile strength among various strengthening contributors. Further analyses reveal that multiple nanoscale stacking-fault (SF) networks are activated during plastic deformation in the aged alloy. Accordingly, the dual effects consisting of the hierarchical precipitation structure and SF networks lead to the combination of excellent tensile strength and strain-hardening capacity.

Effect of multiple laser remelting on microstructure and corrosion resistance of Fe0.5CoCrNi1.5Nb0.68Mo0.3 high entropy alloy coatings

High entropy alloy (HEA) coatings of Fe0.5CoCrNi1.5Nb0.68Mo0.3 was prepared on 304 stainless steel using laser cladding and subsequently remelted multiple times. The effects of multiple thermal cycles on the phase composition, grain size, microstructure evolution, and corrosion resistance of the coatings are thoroughly investigated. The original coating consisted of face-centered cubic (FCC), Laves, and NbC phases, and the phase composition does not change obviously, but the distribution and microstructure of the phase change significantly after multiple remelting. As the number of remelting times increased, the bar-like eutectic structure decreased while the lamellar eutectic structure became more prominent. Laser remelting induced dynamic recrystallization in the coating, resulting in a transformation from columnar grains to equiaxed grains, and then back to columnar grains. The grain size also changes significantly with different remelting times. Potentiodynamic polarization and electrochemical impact spectroscopy measurements were conducted in a 3.5 wt% NaCl solution to evaluate the corrosion resistance of the coating. The results revealed both the original coating and the once-remelted coating exhibited lower corrosion current density and higher corrosion potential, but the latter had a higher Faraday impedance. Additionally, immersion tests were performed in 10 wt% FeCl3 solution, which demonstrated that the once-remelted coating displayed fine and uniform corrosion pits with shallow depth. This study provides theoretical support for the regulation of microstructure and the optimization of coating performance. Furthermore, the microstructure evolution law discovered in this research is also applicable to additive manufacturing.

TiZrHfNb refractory high-entropy alloys with twinning-induced plasticity

The twinning-induced plasticity (TWIP) effect has been widely utilized in austenite steels, β-Ti alloys, and recently developed face-centered-cubic (FCC) high-entropy alloys (HEAs) to simultaneously enhance the tensile strength and ductility. In this study, for the first time, the TWIP effect through hierarchical {332<113> mechanical twinning has been successfully engineered into the TiZrHfNb refractory HEAs by decreasing temperature and tailoring the content of Nb to destabilize the BCC phase. At cryogenic temperature, the comprehensive hierarchical {332}<113> mechanical twins are activated in TiZrHfNb0.5 alloy from micro- to nanoscale and progressively segment the BCC grains into nano-scale islands during deformation, ensuring sustainable strain hardening capability and eventually achieving a substantial 35% uniform tensile elongation. In addition, at 77 K, the tensile strength and uniform elongation of TiZrHfNbx alloys can further be adjusted by a moderate increase of Nb. The results above shed new light on the development of high-performance refractory HEAs with a high and adjustable strength and ductility combination down to the cryogenic temperature.

Effect of rolling on the microstructure and mechanical properties of (FeCrNi)94Ti3Al3 medium entropy alloy fabricated via selective laser melting

The microstructure evolution and mechanical properties of the (FeCrNi)94Ti3Al3 medium entropy alloy, fabricated through selective laser melting, were investigated after warm-rolling. The as-built (FeCrNi)94Ti3Al3 alloy exhibited a heterogeneous microstructure with alternating coarse face-centered cubic (FCC) phase grains (∼20 μm) and fine body-centered cubic (BCC) phase grains (∼1 μm). However, after warm-rolling and subsequent recrystallization, the alloy transformed into a dual-phase equiaxed grains structure consisting of FCC and BCC phases with an average grain size of approximately 2.8 μm. Additionally, the previously banded distribution of the BCC phase changed to a random distribution. Notably, during the deformation process, a twinning-induced plasticity (TWIP) effect was observed in the warm-rolled and recrystallized (FeCrNi)94Ti3Al3 alloy, resulting in excellent ductility and a wide work-hardening platform.

Cooperative dislocations for pressure-dependent sequential deformation of multi-principal element alloys under shock loading

Multi-principal element alloys (MPEAs) are promising materials for structural applications under extreme conditions. Their outstanding mechanical properties are closely related to the activation of multiple deformation modes of dislocation gliding, twinning, and phase transformation that appear in sequence during deformation at low temperatures, high pressures, or high strain rates. However, the inherent correlations among these deformation modes and, thus, underlying deformation mechanisms of MPEAs remain largely unknown. We report soft-recovery plate impact experiments of face-centered-cubic (FCC) CrCoNi MPEAs, demonstrating pressure-dependent deformation modes from low-pressure stacking faults to medium-pressure twinning and high-pressure FCC to hexagonal-close-packed (HCP) phase transformation. Atomic-scale characterizations unveil that the sequential deformation is manipulated by the cooperation of 90° and 30° Shockley partial dislocations at deformation fronts, which is facilitated by low stacking fault energy and pressure-dependent phase stability of the MPEAs. Moreover, the cooperative dislocation behavior can also be observed at twin fronts of shock-loaded CrMnFeCoNi MPEA, validating the universality of the cooperative deformation mode in FCC alloys with a low stacking fault energy. Theoretical analyses suggest that the distinctive cooperative dislocation behavior results in the self-compensation of dislocation strain fields and the minimization of interfacial elastic energy at incoherent twin and FCC/HCP interfaces.

Mechanical response and microstructural evolution of a composite joint fabricated by green laser dissimilar welding of VCoNi medium entropy alloy and 17-4PH stainless steel

In engineering structures, the application of advanced alloys, such as the VCoNi medium-entropy alloy (VCoNi-MEA), with remarkable tensile strength (> 1 GPa) and superior ductility necessitates the employment of dissimilar joints. This study pioneers the dissimilar joining of VCoNi-MEA and 17–4 precipitation hardening stainless steel (17–4PH STS) using state-of-the-art green laser beam welding (LBW). To evaluate and optimize the experimental parameters, two welding speeds (200 and 300 mm/s) along with post-weld heat treatment (PWHT) were incorporated. High-quality welded joints with a single-phase face-centered cubic (FCC) structure in the fusion zone (FZ), minimal precipitates (< 1.6 %), and no visible cracks were successfully created. The LBW process demonstrated effective low-heat input characteristics, evident from a considerably narrow heat-affected zone (HAZ). Control over FZ width and grain size was achieved, measuring 600 and 112 μm at low welding speed and 250 and 49 μm at high welding speed, respectively, significantly lower than previous studies. A remarkably high yield strength (YS) of ∼620 MPa and ultimate tensile strength (UTS) up to 845 MPa were observed in the as-welded conditions, improving to ∼645 and 875 MPa, respectively, after PWHT. This enhancement in mechanical properties is primarily attributed to lattice friction induced by V addition. PWHT also improved joint ductility, increasing from 3.5 % to 8.6 % (low-speed) and from 6.3 % to 9.2 % (high-speed). The reduction in crystallographic orientation achieved using a higher welding speed and PWHT emerged as a major reason for improved mechanical properties. Slip-based deformation mechanisms dominated across all conditions, featuring crystallographically aligned slip bands. Interactions between existing and additional slip bands formed a dense dislocation network crucial for enhanced elongation after PWHT. Thermodynamic parameters elucidating phase stability in the observed FZs and contributions to superior YS were calculated and comprehensively discussed.