Solute Partitioning Research Articles

Direct mixed-mode I&II partitioning in beam-like geometries using Digital Image Correlation and the decomposed [formula omitted]-integral

In the current work, a direct method of mode partitioning is developed, based on the application of the partitioned J-integral to strain fields directly measured using Digital Image Correlation. The method has first been validated using strain fields obtained from Finite Element Analysis of Double Cantilever Beam, End-Loaded Split and Fixed-Ratio Mixed-Mode test specimen geometries. Then, a Cracked Lap Shear specimen has been designed, modelled and tested. Very good agreement was achieved for all standard specimens. As for the Cracked Lap Shear geometry, there are no accepted partitioning solutions. The new direct mixed-mode partitioning method results in GIGII=0.35. This method has also been successfully extended to asymmetric cases using the Asymmetric Fixed Ratio Mixed Mode test specimen with 5 different beam thickness ratios: γ = 0.5, 1, 1.8, 3 & 3.94. The results are found to compare very well with both FEA and the semi-analytical cohesive analysis (SACA) partitioning method from Conroy et al. (2015).

Hierarchical Analysis of Protein Structures: From Secondary Structures to Protein Units and Domains.

The three-dimensional structure of proteins is traditionally organized into hierarchical levels, specifically secondary structures and domains. However, different studies suggest the existence of intermediate levels, such as Protein Units (PUs), which provide a refined understanding of protein architecture. PUs, characterized by their compactness and independence, serve as an intermediate organizational level, bridging the gap between secondary structures and domains. This new view not only enhances our comprehension of protein structure, folding, and evolutionary mechanisms but also provides a robust methodology for identifying and categorizing protein domains. Based on the concept of PUs, alternative structural partitioning solutions can be proposed that address the structural ambiguity of proteins, leading to more meaningful domain identification.

Micellar solubility and co-solubilization of fragrance raw materials in sodium dodecyl sulfate and polysorbate 20 surfactant systems.

The aim of this work was to investigate the solubility and co-solubilization of fragrance raw materials (FRMs) in sodium dodecyl sulfate (SDS) and polysorbate 20 (P20) surfactant micellar systems, which can advance our knowledge of multi-solute micellar solubilization and fragrance olfactory performance from product matrices containing the surfactants. The transfer of individual FRMs and binary FRM mixtures into micellar phases was quantified by UV-VIS differential spectroscopy and evaluated in terms of the standard Gibbs free energy change and micelle-water partition coefficient. Co-solubilization effects were further evaluated by the deviation ratio. Anionic SDS was found overall to be a more efficient solubilizer than nonionic P20. On an individual basis, micellar solubilization generally increased with solute lipophilicity but was additionally impacted by solute rigidity and steric effects. Micellar solubilization was favoured for more rigid structures and less favoured for FRMs that exhibited larger molecular rotation and steric hindrance. For multi-solute systems, three co-solubilization effects were observed: (i) inhibitive effect in which micellar partitioning of both solutes decreased, (ii) an inverse effect where partitioning of one solute increased while the other decreased and (iii) synergistic effect in which partitioning of both solutes increased. During co-solubilization in P20 micelles, many FRMs competed for solubilization between the polyoxyethylene chains in the outer layer of the micelle, thereby resulting in an inhibitory effect for both solutes. Co-solubilization of FRM binary mixtures in SDS micelles often resulted in a synergistic increase in micellar solubility, possibly due to micellar swelling, thereby facilitating partitioning of additional solutes into the micelle. An inverse effect in which the micellar solubility of one solute increased, while the other decreased was observed in both surfactant systems with varying degrees of partitioning depending on the composition of the FRM mixture. The results of this study provide valuable insights into the impact of FRM composition on multi-solute partitioning behaviour and the impact of surfactant type on co-solubilization in micellar solutions.

Quantifying steric, non-steric, and adsorption contributions to solute rejection in covalent organic framework nanofiltration membranes

Solute transport in nanofiltration (NF) membrane systems is described with the Donnan Steric Pore Model with Dielectric Exclusion (DSPM-DE), which couples size- and charge-based solute partitioning mechanisms into and out of the membrane pores with flow through the pore, as described by the Extended Nernst-Planck equation. If membrane structural and chemical characteristics are well defined, the DSPM-DE can theoretically be used to identify solute rejection mechanisms, predict NF performance, and guide membrane design. However, the presence of additional separation mechanisms, like adsorption, and the heterogeneous, convoluted characteristics of traditional NF membranes challenge these goals. In this work, we apply covalent organic frameworks (COFs) as model NF materials to demonstrate control over the steric and non-steric partitioning and transport mechanisms in NF. We experimentally isolate and quantify the steric and non-steric contributions to solute partitioning and transport in NF via application of the DSPM-DE to COF membranes fabricated with tailored pore sizes, thicknesses, and charge properties. We also demonstrate enhanced non-steric solute rejection achieved through changes to COF membrane structure and chemistry, and we highlight the significant impact of adsorption on measured solute rejection by COF membranes.

Effect of GPa-level pressure on the microstructure and properties of Cu-8Ni-1.8Si alloy

Reducing or completely eliminating the reticular grain boundary phases in alloys is crucial for enhancing the mechanical and electrical properties of Cu-Ni-Si alloys with high nickel and silicon content (Ni + Si > 5wt.%). In this study, we investigated the microstructure, mechanical properties, and electrical conductivity of Cu-8Ni-1.8Si (wt.%) alloy prepared by high-pressure solidification (HPS) and subsequent aging treatment. The interfacial growth stabilizes as the pressure reduces the crystal growth rate, inhibits the diffusion of solute atoms, and increases the solute partition coefficient. The reticulated Ni31Si12 and granular Ni2Si phases disappear under 6GPa pressure, forming a complete Cu (Ni, Si) solid solution. After direct aging treatment, the precipitated phase of the HPS alloy is β-Ni3Si at the early stage of aging. At the peak aging state, β-Ni3Si and δ-Ni2Si phases coexist in the matrix. Additionally, the Avrami equations for the phase transition kinetics of HPS alloys at different aging temperatures were derived from the electrical conductivity data, and the strength contributions from solid solution strengthening and precipitation strengthening were calculated. The alloy aged at 450 °C exhibited the largest volume fraction and the smallest average size of precipitates, resulting in a more pronounced obstruction effect of nano precipitates on dislocation bypassing and demonstrating the best precipitation strengthening effect. At the peak aging states, the alloy's hardness reaches 367.5 HV, and the compressive yield strength reaches 788.2MPa. These results indicate that high pressure is an effective method to improve the solid solution degree of alloying elements and enhance the mechanical properties of Cu-Ni-Si alloys.

Integrita: A BFT distributed storage system

Collaborative data sharing underlies applications in systems such as online social networks and cloud storage. A central provider hosts shared data, e.g., a Facebook group page, and provides sharing users with read/write access according to user-defined settings. Historical incidents prove that data storage centralization enables a corrupted provider to censor or diverge users’ views of the shared data. Such misbehavior is hardly detectable as users update the shared data unbeknown to each other. Existing solutions suggest server-side data replication, which is storage inefficient, or users’ out-of-band communication, which is communication intensive. Addressing these inefficiencies, we propose Integrita, a data-sharing mechanism that protects users’ view- consistency needless to out-of-band communication. We present a novel distributed history tree algorithm to partition the shared data among N storage providers, N−1 of which are Byzantine faulty and colluding. Our data partitioning solution reduces storage overhead by a multiplicative factor of N and allows provable detection of server-side equivocation and identification of corrupted servers. We introduce and achieve a new consistency level, named q-detectable consistency, where users’ views inconsistency cannot remain undetected for more than q updates, q being the system parameters’ function. Without loss of generality, we use online social networks as a case study to deploy Integrita and supply performance/numerical analysis accordingly. i

Graph convolutional network for water network partitioning

The partitioning of a water distribution network into several district-metered areas (DMAs) yields is of great benefits for the management of water distribution systems, including enhanced leak control, pollution monitoring, and pressure optimization. However, achieving an effective partitioning that simultaneously incorporates node characteristics and network connections is challenging. Previous studies have tackled water network partitioning by focusing on either node features or pipe connections individually. In response to the limitations of current approaches for water distribution network partitioning, this study introduces an innovative unsupervised clustering approach for node partitioning based on graph convolutional network (GCN) techniques. Initially, the network nodes are clustered using the Cross-Attention Fusion Based Enhanced Graph Convolutional Network (CaEGCN) deep clustering algorithm, considering both the network’s topological layout and hydraulic properties. The resulting clusters categorize the network nodes into distinct regions. We evaluate our approach and other methods through a real world water distribution network using five different metrics commonly used to evaluate applied in assessing water supply network zoning issues. By comparing and analyzing the performance of experiments with other schemes, the experimental results demonstrate that the CaEGCN deep clustering method featured a remarkable performance. The proposed method showcases its potential for practical application by offering a dependable and easily interpretable water network partitioning solution.

Solvent screening for the purification of monoterpenoids by countercurrent and centrifugal partition chromatography

AbstractBACKGROUNDCountercurrent chromatography (CCC) and centrifugal partition chromatography (CPC) are efficient techniques to purify terpenoids from essential oils. These methods require suitable solvent systems for the partition between the two immiscible liquid phases. In this study, using the analytical shake‐flask method, we measured the partition coefficients of three model monoterpenoids, namely carvone, eucalyptol and thymol, in 11 biphasic solvent systems, at 298.2 K. Moreover, the predictive COSMO‐RS model was applied to represent the partition coefficients of data measured in this work and retrieved from the literature, the liquid–liquid equilibrium (LLE) data of three solvent families suitable for CCC/CPC separations (i.e., Arizona, Modified Arizona and Green Arizona) and the solute's partition coefficients in the three solvent families.RESULTSThe partition coefficients obtained for thymol and eucalyptol are the first partition data available in the literature. The obtained root mean square deviations (RMSDs) between the experimental and predicted partition coefficients (log basis) varied between 0.28 and 0.49. For LLE, RMSDs of 0.040 and 0.048 were achieved for the Arizona and Green Arizona families, respectively.CONCLUSIONThe predictive COSMO‐RS model describes the monoterpenoid partition coefficients and the LLE data of the solvent families well. The most favorable solvent systems to perform the separations were identified, showing that systems with low and intermediate‐to‐low polarities are the most promising options for separating the selected monoterpenoids from their natural matrices by CCC/CPC techniques. © 2024 Society of Chemical Industry (SCI).

Probing the formation mechanism of hierarchical microstructures in experimental Ni-based superalloys

Hierarchical microstructures, consisting of a γ matrix with γ′ precipitates that incorporate finer-scale embedded γ precipitate, are known to enhance strength and enhanced coarsening resistance of the ordered γ′ precipitates in various nickel-based superalloys. Despite their potential benefits, the underlying origins and design principles of such hierarchical microstructures remain poorly understood due to the complex multicomponent nature of superalloys. In this study, we employ an integrated approach that combines advanced composition and microstructure analysis and computational thermodynamic and kinetic modeling to investigated the formation mechanism of the hierarchical microstructure in two experimental multi-component nickel-base superalloys. Using chemical mapping via atom probe tomograph and nucleation driving force calculations, we find that the enrichment of γ-stabilizing elements, such as Co and Cr, along with the depletion of Al within the γ′ precipitates, promotes the decomposition of the γ′ phase and the precipitation of the finer γ phase. In addition, kinetic modeling predicts the supersaturation of Co and Cr during cooling, elucidating the influence of heat treatment on solute partitioning. Our findings illustrate how alloy composition and tailored heat treatment strategies discussed can guide the design of a hierarchical γ/γ’/γ microstructure, offering a pathway towards optimizing mechanical properties in nickel superalloys through microstructure design.

A lattice Boltzmann model with sharp interface tracking for the motion and growth of dendrites in non-equilibrium solidification of alloys

A lattice Boltzmann model (LBM) with sharp interface tracking is developed to simulate the motion and growth of dendrites in non-equilibrium solidification of alloys. The model is validated through comparative analysis with the drafting-kissing-tumbling (DKT) phenomena of two and three particles and the continuous growth model (CGM), and demonstrates its computational efficiency advantage without compromising accuracy by comparison with the multi-phase field (MPF) model. Subsequently, the model is utilized to investigate the dendrite morphology transition and primary dendritic arm spacing (PDAS). It is found that the velocity dependent solute partition and the resulting changes in constitutional undercooling strongly influence the estimated morphology region and PDAS. Moreover, the segregation and microstructure evolution during the rapid solidification were studied. And the results revealed that free dendrites lead to significant changes in microstructure and segregation under the influence of non-equilibrium effects. This work illustrates the great potential of the proposed model in simulating dendrites and microstructure evolution under a wide range of solidification conditions. Its suitability for extreme conditions and non-equilibrium solidification can contribute to the understanding of microstructure formation patterns and solute segregation in rapid solidification.

Solute-induced transition in Poisson's ratio and strength: A phenomenon in additively manufactured Al-Si-Mg alloys

In this study, cubic coupons of AlSi10Mg alloy were printed using the laser powder bed fusion (LPBF) technique. The effect of heating/reheating cycles on solute trapping and partitioning of alloying elements was investigated using atom probe tomography and transmission electron microscopy. Nano-hardness analysis and uniaxial tensile tests equipped with digital image correlation were employed to investigate the mechanical properties and Poisson's ratio. X-ray micro-computed tomography was utilized to detect strain localization sites along the building direction. Also, the uniaxial tensile test was simulated using finite element analysis to verify the experimental data and predict stress triaxiality. The results showed that the solute trapping and partitioning during the LPBF process results in remarkable changes in phases, their size and morphology, Poisson's ratio, strengthening factor, and consequently mechanical properties. While the tensile sample from top part of the LPBF coupon mostly shows porosity due to floating and entrapment of gases during layer-by-layer fusion/solidification, the sample from bottom part is exposed to sub-surface microcracking induced by residual stresses. The hardness, elastic, and shear moduli, Peierls stress, and cumulative strain energy of the top-part sample are higher than those of the bottom-part sample even though electron backscatter diffraction analyses report similar grain size and texture. Besides, by distancing from the build plate, the Poisson's ratio decreases. Simulation results of both samples indicate that the middle of the gauge is a high-potential area of failure initiation, where the bottom-part sample shows higher stress localization.

Effects of L12 precipitates containing Zr, Er, and Y on the precipitation of Al–Zn–Mg alloys at elevated temperatures

Microalloying significantly enhances the high-temperature properties of nano-precipitates through solute partitioning at elevated temperatures. In this study, we investigated the effects of L12 crystal structural precipitates containing Zr, Er, and Y influence the precipitation of Al–Zn–Mg alloys using transmission electron microscopy and atom-probe tomography. The results demonstrate that the multi-addition of Zr, Er, and Y improves both ambient and high-temperature hardness of Al–Zn–Mg alloys by increasing the number density of precipitates and preventing coarsening of L12/η-MgZn2 type nano-precipitates during over-aging period at elevated temperatures. Particularly, Y forms a thermally stable L12 precipitate through multiple additions with Zr and Er, a finding supported by atom-probe tomography, which reveals a synergistic interaction between Er and Y. The Er and Y multi-addition increases the number density of fine L12-Al3(Zr, Er, Y) precipitates, providing heterogeneous nucleation sites for η-type nano-precipitates at the interfaces between L12/η precipitate, thereby increasing the formation of fine η-type nano-precipitates during the over-aging period.

Exploring the Distribution of Low Molecular Weight Compounds in Water-Based Two-Phase Systems with Various Salt Additives

The partition coefficients of seven low molecular weight compounds were tested in different aqueous two-phase systems. The ionic composition of each system included specific salt additives, and it was found that there is a linear relationship between the solute partition coefficients and the presence of different salt additives. The study suggests that the solute structure and the type of ions influence the solute response to the ionic environment. Additionally, it was observed that the solutes’ polar surface area and the solvent-accessible surface area are the essential structural features governing partitioning in aqueous two-phase systems.

Cenozoic Carbon Dioxide: The 66 Ma Solution

The trend in partial pressure of atmospheric CO2, P(CO2), across the 66 MYr of the Cenozoic requires elucidation and explanation. The Null Hypothesis sets sea surface temperature (SST) as the baseline driver for Cenozoic P(CO2). The crystallization and cooling of flood basalt magmas is proposed to have heated the ocean, producing the Paleocene–Eocene Thermal Maximum (PETM). Heat of fusion and heat capacity were used to calculate flood basalt magmatic Joule heating of the ocean. Each 1 million km3 of oceanic flood basaltic magma liberates ~5.4 × 1024 J, able to heat the global ocean by ~0.97 °C. Henry’s Law for CO2 plus seawater (HS) was calculated using δ18O proxy-estimated Cenozoic SSTs. HS closely parallels Cenozoic SST and predicts the gas solute partition across the sea surface. The fractional change of Henry’s Law constants, Hn−HiHn−H0 is proportional to ΔP(CO2)i, and Hn−HiHn−H0×∆P(CO2)+P(CO2)min, where ΔP(CO2) = P(CO2)max − P(CO2)min, closely reconstructs the proxy estimate of Cenozoic P(CO2) and is most consistent with a 35 °C PETM ocean. Disparities are assigned to carbonate drawdown and organic carbon sedimentation. The Null Hypothesis recovers the glacial/interglacial P(CO2) over the VOSTOK 420 ka ice core record, including the rise to the Holocene. The success of the Null Hypothesis implies that P(CO2) has been a molecular spectator of the Cenozoic climate. A generalizing conclusion is that the notion of atmospheric CO2 as the predominant driver of Cenozoic global surface temperature should be set aside.

Microstructure and Properties of Complex Concentrated C14–MCr2 Laves, A15–M3X and D8m M5Si3 Intermetallics in a Refractory Complex Concentrated Alloy

Abstract: The refractory complex concentrated alloy (RCCA) 5Al–5Cr–5Ge–1Hf–6Mo–33Nb–19Si–20Ti–5Sn–1W (at.%) was studied in the as-cast and heat-treated conditions. The partitioning of solutes in the as-cast and heat-treated microstructures and relationships between solutes, between solutes and the parameters VEC and Δχ, and between these parameters, most of which are reported for the first time for metallic UHTMs, were shown to be important for the properties of the stable phases A15–Nb3X and the D8m βNb5Si3. The nano-hardness and Young’s modulus of the A15–Nb3X and the D8m βNb5Si3 of the heat-treated alloy were measured using nanoindentation and changes in these properties per solute addition were discussed. The aforementioned relationships, the VEC versus Δχ maps and the VEC, Δχ, time, or VEC, Δχ, Young’s modulus or VEC, Δχ, nano-hardness diagrams of the phases in the as-cast and heat-treated alloy, and the properties of the two phases demonstrated the importance of synergy and entanglement of solutes, parameters and phases in the microstructure and properties of the RCCA. The significance of the new data and the synergy and entanglement of solutes and phases for the design of metallic ultra-high temperature materials were discussed.

Understanding the solute segregation and redistribution behavior in rapidly solidified binary Ti-X alloys fabricated through non-equilibrium laser processing

The solute segregation and redistribution during non-equilibrium rapid solidification using laser additive manufacturing (LAM) process directly influence the microstructure morphology and phase distribution, which in turn affects their mechanical properties. In this work, a laser micro-alloying strategy was utilized to preserve the original solidification microstructure in the considered Ti-9Mo, Ti-9Cr, Ti-9Fe, and Ti-9Ni (wt.%) alloys. The addition of different β-stabilizing elements (Mo, Cr, Fe, and Ni) resulted in distinct microstructures: Ti-9Mo and Ti-9Cr alloys exhibited larger grains (~502 μm and ~733 μm) and cellular morphologies due to minimum constitutional undercooling at the solid-liquid interface. Because of the increased constitutional undercooling, the Ti-9Fe grains are significantly refined (~398 μm), showing a dendritic morphology with elongated primary dendrite arms. Ti-9Ni exhibited the highest constitutional undercooling, forming equiaxed dendrites. However, due to the significant consumption of solute atoms by the interdendritic eutectic phase Ti2Ni, the grains did not further refine (~396 μm). Combined with the temperature field simulation, the solidification conditions of the alloys were determined. In addition, based on the solute partitioning coefficients (k), the different solute redistribution and diffusion behaviors at the solid-liquid interface during the laser micro-alloying process of Ti-9Mo with k > 1 and Ti-9Cr with k < 1 were elucidated, providing essential insights into the formation of typical cellular morphology and enhanced Mo enrichment phenomenon in the Ti-9Mo alloy.

Fabrication of highly heterogeneous precipitate microstructure in an α/β titanium alloy

To obtain a synergistic combination of high strength and high ductility in titanium alloys, design and creation of heterogenous precipitate microstructure have attracted increasing attention. Herein, using Ti-3Al-5Mo-4.5V (wt.%, an α/β titanium alloy) as a model alloy, we demonstrated that a highly heterogenous α-phase precipitate microstructures with well-controlled length scale of spatial heterogeneity (i.e., micron-sized primary α and nano-scale secondary α precipitates), can be synthesized through activating the ω-assisted α nucleation transformation pathway that operates in metastable β titanium alloy alone. A detailed analysis of transformation pathway for ω phase and the underlying ω-assisted α nucleation mechanisms is carried out using the integrated advanced characterizations, theoretical calculations and simulations based on DFT, and phase-field modeling. Experimental results show unambiguously that the embryonic ω particles (also known as athermal ω) with partially collapsed structure are incapable of refining secondary α (αs). In contrast, the isothermal ω particles with a complete structural collapse play an important role in assisting αs nucleation, resulting in the formation of the ultrafine αs lamellae at nanoscales after two-step aging heat treatments. The contributions from the isothermal ω particles are then quantified using first-principles calculations and phase-field simulations. It is found that, even though the solute partitioning between a growing isothermal ω particle reduces the αs nucleation driving force in the surrounding β matrix, the elastic interaction between the ω particles and the αs nucleus provides more driving force for αs nucleation at specific locations of the ω/β interface. Our work extends the microstructure design strategy based on ω-assisted α nucleation mechanism from metastable β to α/β Ti-alloys, thereby significantly widening the application space of the strategy.

Novel Fe-Mo intermetallic composite synthesized via diffusional-displacive mixed-mode transformation

Transition metal-based intermetallic materials are candidates for high-temperature structural applications. However, they are limited by their low fracture toughness at ambient temperature. Given Fe is a low-cost metal with a low environmental impact, it is necessary to design tough Fe-based intermetallic alloys. We report a novel ferrite-Fe2Mo intermetallic synthesized through arc melting and quenching of Fe0.78Mo0.22 alloy. Diffusional-displacive mixed-mode transformation of the parent ferrite phase resulted in the formation of nanocomposite microstructure. Two distinct microstructure morphologies of the product μ phase were observed: (i) allotriomorphic phase formation at the parent ferrite grain boundaries and (ii) formation of basket-weave Widmanstätten structures at the parent grain interior. Electron probe microanalysis (EPMA) revealed Mo partitioning across ∼800 nm wide Widmanstätten laths, establishing that it is a diffusional-displacive mixed-mode transformation. We performed atom probe tomography (APT) investigations to ascertain the nanoscale Mo solute partitioning. Based on the chemistry of the retained parent ferrite, the Mo partitioning temperature was estimated to be ∼865 °C. Mo partitioned Widmanstätten lath formation is clarified using a shear-assisted diffusional transformation model. APT studies further revealed that the composition of the product μ phase corresponds to stoichiometric Fe2Mo. It is an anomaly since stoichiometric Fe2Mo typically corresponds to λ C14 Laves phase. We explain the mechanism of μ phase formation with Fe2Mo stoichiometry. The nanocomposite exhibits a high hardness (HV2) of 7.54 GPa and excellent toughness (evidenced by resistance to indentation cracking).

Thermo-kinetic insights into deformation mechanism in the phase-transforming nanostructured Fe alloy

Solid-state phase transformations (SSPTs) being the most widely versatile routes to tailor microstructures are less utilized in the design of nanostructured (NS) alloys, resulting in a lack of understanding of the significance of SSPTs in tuning mechanical properties. Here, we combine nanostructuring with reverse austenite transformation to make a phase-transforming NS Fe alloy consisting of ultrafine ferrite and austenite grains. By comparison with the coarse-grained (CG) counterpart, the NS sample exhibits high strengths (i.e., the yield and the ultimate tensile strengths are 816 and 1170 MPa, respectively), good ductility with a uniform elongation of 53 %, and superior strain hardening capacity, under multiple strengthening mechanisms and the activation of transformation induced plasticity. Regarding the mechanism in forming the NS sample, grain refinement is revealed to markedly affect the austenite formation kinetics by generating sluggish growth behavior accompanied by sufficient solute partitioning. Then, we clarify the difference in mechanical responses of the phase-transforming NS and CG samples using a physically based microstructures-properties model. Further based on the thermo-kinetic theory of generalized stability, we show that the simultaneous increase of strength and ductility in the NS sample relative to the CG sample is originated from the deformation physics with higher driving force and higher generalized stability. From the thermo-kinetic perspective, our work demonstrates that the SSPTs hold substantial promise in optimizing the microstructures and the mechanical properties of NS Fe alloys and are expected to find wide application in the development of other NS materials.

Role of the aging procedure on the ω + β microstructure in the metastable β Ti-30Nb-3Fe alloy

This report investigated the effect of low-temperature aging on the ω + β microstructure in the Ti-30Nb-3Fe alloy (wt%). Samples were subjected to several aging procedures. The ω + β microstructure remained quite stable under conventional transmission electron microscopy across most temperature/time regimes. Only the double aging treatment led to the growth of ω particles and an increased in Vickers hardness, indicating that the pre-aging treatment was necessary to promote rapid ω growth in the subsequent treatment. Furthermore, the early stages of solute partitioning that accompanies ω growth did not drastically increase hardness, suggesting that no embrittlement occurred.