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By employing non-equilibrium molecular dynamics (NEMD) simulations and time-dependent Ginzburg–Landau (TDGL) theory for solidification kinetics [Cryst. Growth Des. 20, 7862 (2020)], we predict the kinetic coefficients of FCC(100) crystal–melt interface (CMI) of soft-spheres modeled with an inverse-sixth-power repulsive potential. The collective dynamics of the local interfacial liquid phase at the equilibrium FCC(100) CMIs are calculated based on a recently proposed algorithm [J. Chem. Phys. 157, 084 709 (2022)] and are employed as the resulting parameter that eliminates the discrepancy between the predictions of the kinetic coefficient using the NEMD simulations and the TDGL solidification theory. A speedup of the two modes of the interfacial liquid collective dynamics (at wavenumbers equal to the principal and the secondary reciprocal lattice vector of the grown crystal) is observed. With the insights provided by the quantitative predictive theory, the variation of the solidification kinetic coefficient along the crystal–melt coexistence boundary is discussed. The combined methodology (simulation and theory) presented in this study could be further applied to investigate the role of the inter-atomic potential (e.g., softness parameter s = 1/n of the inverse-power repulsive potential) in the kinetic coefficient. [ABSTRACT FROM AUTHOR]

Advances in cryobiology techniques commonly target either the cooling or the warming cycle, while little thought has been given to ≪repair≫ protocols applicable during cold storage. In particular, crystallization is the dominant threat to cryopreserved samples but proceeds from small nuclei that are innocuous if further growth is forestalled. To this end, we propose a laser editing technique that locally heats individual crystals above their melting point by a focused nanosecond pulse, followed by amorphization during rapid resolidification. As a reference, we first apply the approach to ice crystals in cryoprotected solution and use Raman confocal mapping to study the deactivation of crystalline order. Then, we examine dimethyl sulfoxide trihydrate crystals that can germinate at low temperatures in maximally freeze concentrated regions, as commonly produced by equilibrium cooling protocols. We show how to uniquely identify this phase from Raman spectra and evidence retarded growth of laser-edited crystals during warming. [ABSTRACT FROM AUTHOR]

In this paper, we demonstrate that the weak temperature dependence of the structure factor of supercooled liquids, a defining feature of the glass transition, is a consequence of the averaging of the scattering intensity due to angular averaging. We show that the speckle at individual wavevectors, calculated from a simulated glass former, exhibits a Debye–Waller factor with a sufficiently large temperature dependence to represent a structural order parameter capable of distinguishing liquid from glass. We also extract from the speckle intensities a quantity proportional to the variance of the local restraint, i.e., a direct experimental measure of the amplitude of structural heterogeneity. [ABSTRACT FROM AUTHOR]

This work was designed to investigate the influence of arsenic dosage, variety on the mechanical properties, hydration, and solidification from the perspective of Portland cement (PC) performance evolution. The results demonstrate that using PC could solidify the arsenic wastes effectively, with arsenic leaching concentrations consistently below 5 mg/L. Arsenic wastes retard cement hydration, leading to a slower rate of hydrates formation, disrupting the calcium silicate hydrate (C–S–H) stacking structure, and thus detrimental to strength development especially at early age. The adverse effect is highly dependent on the arsenic variety. The insoluble calcium arsenate exhibits the least impact, while the arsenates show the largest challenging to immobilization due to the instability of hydrates. Molecular dynamic simulation indicates that arsenic can be chemically immobilized with Ca2+, and be physically adsorbed onto the positively charged C–S–H by forming As‐O···Ca···Si‐O units, accompanied by a significant reduction in adsorption energy by 46.5%. The arsenic solidification behavior provides a basis for the resource utilization of arsenic wastes in cementitious materials. [ABSTRACT FROM AUTHOR]

This work evaluates the use of zinc oxide nanorods as intensifiers of a latent heat thermal energy storage system working with adipic acid as the phase change material (PCM). By virtue of not participating directly in the solid–liquid and liquid–solid phase transition, ZnO-adipic acid composites (ZnO-adipic acid) possessed lower specific heat and latent heat. Our results have shown that the overall heat transfer coefficient during the freezing of PCM through heat transfer to a well-mixed liquid bath is amplified by 61%, when adipic acid is replaced with 2 wt.% ZnO-adipic acid. Heterogenous nucleation due to well-dispersed, ZnO nanorods caused this enhancement. The large enhancement in discharge rate of 2 wt.% ZnO-adipic acid during freezing overweighs higher degree of latent heat loss due to its repeated thermal cycling. The enhancement in overall heat transfer coefficient reported here (61%) is the highest reported so far for any latent heat thermal energy system employing adipic acid or its composites. [ABSTRACT FROM AUTHOR]

Due to their unique mechanical and thermal properties, polyurethane foams are widely used in multiple fields of applications, including cushioning, thermal insulation or biomedical engineering. However, the way polyurethane foams are usually manufactured ‐ via chemical foaming ‐ produces samples where blowing and gelling occur at the same time, resulting in a morphology control achieved by trial and error processes. Here, a novel strategy is introduced to build model homogeneous polyurethane foams of controlled density with millimetric bubbles from liquid templates. By producing a polyurethane foam via physical bubbling without a catalyst and gently depositing a secondary foam containing catalyst on the top of this first foam, it is possible to take advantage of drainage mechanisms to trigger the solidification of the bottom foam. The characterization of the samples performed by X‐ray microtomography allows to study quantitatively the structure of the final solid foam, at the global and at the local scale. Using the tomographic 3D images of the foam architectures, the superimposed foam technique introduced in this article is shown to be promising to produce foams with a good homogeneity along the vertical direction, with a density controlled by varying the concentration of catalyst in the secondary foam. [ABSTRACT FROM AUTHOR]

During the laser cladding process, poor flatness of the cladding track can cause the surface structure to be uneven or corrugated, affecting the geometrical accuracy of the workpiece. Adjusting process parameters is an effective way to achieve high cladding track flatness. This study established a mesoscale model of the laser cladding process for CoCrMoSi powder to simulate the formation of a single cladding track. Subsequently, the formation mechanism of cladding track flatness was revealed by analyzing the flow within the molten pool and the solidification behavior of the molten pool edge. The influences of laser power, scanning speed, and powder feeding rate on flatness were determined through simulations and physical experiments. Finally, a parameter window of flatness was established using simulation and experimental results. The window indicates that high flatness is achieved with a high scanning speed (v > 260 mm/min), high laser power (P > 2300 W), and low powder feed rate (Pf < 5.5 g/min). The accuracy of the numerical model was verified by comparing the simulated results with the experimental measurements. [ABSTRACT FROM AUTHOR]

The present aims to evaluate the effect of adding Zn (0.5% and 9.0% in wt%) on phase transformation temperatures, microstructure coarsening, solidification parameters (cooling rate‐T˙$T_{\over{.}}$L and growth rate‐VL), macrosegregation, and mechanical properties of directionally solidified Sn‐34wt%Bi‐xZn alloys. The samples have been characterized by optical microscopy, scanning electron microscopy, X‐ray fluorescence, and X‐ray diffraction, in addition to Vickers microhardness and tensile tests. The CALPHAD method has been used for thermodynamic computations via Thermo‐calc software, in order to obtain thermodynamic data. The microstructure of Sn–Bi–Zn alloys is mainly dendritic, composed of a Sn‐rich matrix (β‐Sn) with Bi precipitates inside and surrounded by a Sn+Bi eutectic mixture of phases, predominantly observed at the coarse scale. Coarse Zn needles are also observed in the Sn‐34wt%Bi‐9wt%Zn alloy due to the high Zn content. On the whole, Zn provoked a coarsening of the dendritic arrangement. Moreover, Zn additions cause inverse segregation of Bi, as compared to the rather constant macrosegregation profile observed in the binary Sn–Bi alloy. On the whole, both additions of Zn (0.5 and 9.0) promoted increase in Vickers microhardness, yield strength (σY), and ultimate tensile strength (σu), however, causing an overall reduction in elongation‐to‐fracture (δ). [ABSTRACT FROM AUTHOR]

The efficient processing of hypereutectic Al–Si alloys depends on controlling the microstructure of the primary Si phase during solidification. This study investigates the effects of electric current and phosphorus (P) addition on the refinement of primary Si, with the results confirming that applying electric current during solidification refines the primary Si phase; introducing P further enhances this refinement. Notably, when 10 ppm of P is added (below the identified critical amount of 20 ppm), an improved refinement effect is observed compared with the application of either electric current or P alone. Applying an electric current generates a circulating flow within the melt, resulting in an increased cooling rate, which leads to improved nucleation behavior for the primary Si phase. In addition, the circulating flow generated within the melt influences the dispersion of aluminum phosphide during nucleation. Adding P at concentrations above 40 ppm does not yield further benefits, suggesting a saturation point for its efficacy. This study demonstrates that the concurrent electric current application and minimal P addition can significantly enhance the refinement of primary Si phases, offering a potent approach for optimizing the microstructural properties of hypereutectic Al–Si alloys. [ABSTRACT FROM AUTHOR]

The elaboration of suitable NdFeB‐based permanent magnets is essential for high‐performance electrical machines in a number of applications. In this respect, the understanding of the relationship between heat transfer phenomena and the final solidified microstructure is the key to the control of the grain size and the improvement of the magnetic properties. The problem is even more acute with the emergence of new manufacturing processes, such as the laser powder bed fusion, where the cooling rates are much higher than those encountered in the standard strip casting process and where the microstructure can be considered as fixed from the fabrication step. The objective of the present work is to identify correlations between interstructural spacings in the solidified alloys and cooling conditions. This study is based on a methodology coupling experimental and numerical simulation approaches featuring three solidification processes: strip casting, arc melting, and laser fusion. The obtained results cover more than four orders of magnitude in terms of cooling rates R and allow to propose a reliable empirical relationship between the interstructural spacing λ and R of the form λ [μm] = 83 R [K s−1]−0.36. This relation can thus be used to estimate cooling rates from metallographic observations. [ABSTRACT FROM AUTHOR]

The effect of rapid solidification upon hypereutectic Sn–Ag solder alloy has been investigated using a 6.5 m drop tube. Powder sizes ranging from > 850 to < 38 μm were produced, with equivalent cooling rates of 250 to 14,800 K s−1 for 850 and 38 μm droplets, respectively. At all cooling rates investigated, dendritic β-Sn was observed as the primary solidification phase, not proeutectic Ag3Sn as predicted by the phase diagram. The volume fraction of interdendritic eutectic was observed to decrease with increasing cooling rate, with the Ag concentration in the residual interdendritic liquid estimated at 12.5–15 wt pct Ag, far in excess of the eutectic concentration of 3.8 wt pct. Much of the Ag3Sn observed within the eutectic had a blocky, divorced eutectic appearance. A model is proposed which can explain these observations in terms of sluggish nucleation of the Ag3Sn intermetallic, coupled with a metastable phase diagram that permits significant supersaturation of Ag at modest undercooling. [ABSTRACT FROM AUTHOR]

The microstructure of electronic solder joints is generated by the solidification of a small volume of bulk undercooled liquid. Here, we study β-Sn dendrite growth in Sn–3Ag–0.5Cu in the specific geometry and nucleation conditions of ball grid array (BGA) solder joints by combining electron backscatter diffraction and imaging of microstructures. It is shown that, while ⟨ 110 ⟩ is the preferred dendrite growth direction, out-of-plane branching and growth with ⟨ 11 W ⟩ directions are important for allowing dendrites to fan out into the spheroidal volume of BGA joints due to the low symmetry of β-Sn. We find that the crystallographic orientation of β-Sn at the nucleation point plays a strong role in subsequent dendrite growth. In single-grain joints, dendrites are often unfavorably oriented for growth, resulting in different types of zig-zag dendrite growth. In cyclic-twinned joints, it is shown how competitive out-of-plane trunk growth between three dendrite orientations produces {101} boundaries and the characteristic beachball microstructure. [ABSTRACT FROM AUTHOR]

In this study, the effect of the Fe-rich intermetallic compound phases (IMC) on the solidification cracking susceptibility (Hot Tearing Susceptibility, HTS) of the Al–Mn–Cu alloy and the associated controlling factors were investigated. Using the Al–1.15Mn–1.0Cu–0.5Si–0.08Ti–0.016B–0.15Fe and Al–1.15Mn–1.0Cu–0.5Si–0.08Ti–0.016B–0.4Fe alloys, the HTS and mechanical properties in the partially solidified state were experimentally obtained. As a result, the HTS decreased with the increasing Fe contents. In addition, the tensile strength of the alloys in the partially solidified state (σmax) increased with the increasing Fe contents. The fraction of solid cohesion considering the Fe-rich IMC phase (fsc IMC) based on the Campbell's model (fsc Campbell) is proposed as the controlling factor of σmax. The fsc Campbell, which simulates the two-phases model of the α-Al and liquid phases, did not consistently demonstrate the dependence of σmax on fsc Campbell for the two alloys (σmax = f(fsc Campbell)). However, when employing the fsc IMC, which incorporates the Fe-rich IMC phase in a three-phases model, a consistent correlation is observed between fsc IMC and σmax for the two alloys (σmax = f(fsc IMC)). Therefore, it is suggested that the controlling factor influencing the change in σmax with the Fe content should be the fsc IMC. Additionally, the bonding of primary α-Al phase together with Fe-rich IMC phase that is crystallized at the grain boundary will increase σmax, contributing to the reduction of HTS. [ABSTRACT FROM AUTHOR]

Grain refining is of practical interest in welding, casting, and additive manufacturing. Despite extensive studies, it is still not very clear why grain refining can decrease the susceptibility to cracking during solidification and why over grain refining can increase it. To help understand why, the present study included the continuity of the interdendritic liquid and solute poisoning into consideration. The present study also attempted to estimate the decrease in the cracking susceptibility caused by grain refining. To do this, a simple index for the cracking susceptibility was modified by the extent of grain refining. The validity of the estimation was checked against cracking susceptibility tests in welding and casting. [ABSTRACT FROM AUTHOR]

In DED melt pools, high solidification rates and temperature gradients complicate characterizing competitive dendrite growth. To address this, the WBM phase-field method simulates dendrite growth in the RCF103 alloy, revealing correlations between tilted dendrites and solidification parameters. It explores the competitive mechanism between different dendrite morphologies (columnar and seaweed) and the role of surface energy anisotropy and tip undercooling in determining dendrite shape. These findings enhance our understanding of DED melt pool dendrite growth, facilitating the establishment of a relationship between solidification structure, conditions, and process parameters. [ABSTRACT FROM AUTHOR]

The solidification process and uniaxial tensile test of Al–Cu–Mg alloy at the atomic scale were studied using the molecular dynamics method. The influence of the Mg/Cu ratio on the microstructure and mechanical properties of the Al–Cu–Mg alloy was investigated. The results indicated that during the solidification, the diffusion coefficient of Mg atoms was the lowest, while that of Al atoms was the highest. There may be strong bonding and strong chemical short range ordered structures between Mg–Mg, Al–Cu, and Mg–Cu atoms. As the uniaxial tensile progressed, the alloy exhibited a transformation of FCC→BCC→HCP phase. With increase of the Mg/Cu ratio, HCP and FCC layer-like phases gradually appeared, promoting the occurrence of twins and stacking faults, which resulted in dislocation slip and stress relaxation. As a result, the material become more prone to deformation, leading to a reduction in tensile strength. [ABSTRACT FROM AUTHOR]

In this work, a numerical evaluation of the melting/solidification performance of phase change material (PCM) filled inside a triplex‐tube latent heat storage unit has been carried out. To enhance the melting/solidification performance, the porous Cu metal foam (MF) was embedded inside PCM (termed as composite PCM). Alternative segments of pure PCM and composite PCM have been allocated in such a way that both the pure PCM and composite PCM occupy the equal annular area (i.e., equal volumes). Influence of increasing number of segments was delineated on the melting/solidification rate, complete melting time, and thermal energy storage/recovery enhancement. The comparisons were drawn with reference to the model having two segments of PCM and composite PCM. The results show that the model containing 64 segments with alternate allocations of PCM and composite PCM has a faster melting/solidification rate than other models. With 32 alternate segments of MF, the full melting/solidification time reduced by 23%/77% with respect to the case with one segment of MF only. The melting/solidification performance gets saturated beyond 32 segments (M‐5) and negligible variation (only ~1%) in the thermal performance was noticed upon further segmentation. Finally, the model M‐5 proved as the best model considering the aspects of augmented melting/solidification rate and associated complexities. Moreover, the heterogeneity of MF applied in 32‐segment model confirmed that the anisotropic MF results in an increased melting rate and leads over other random isotropic distributions of MF. [ABSTRACT FROM AUTHOR]

Easy pulverization of FeSi75 alloy during its crushing, storage, and transportation, inducing huge loss of such alloy annually, has been a critical problem. In this research, the pulverization mechanisms of FeSi75 alloy have been understood by introducing a range of characterization techniques to find out correlations between the alloy microstructure, mechanical properties, formation of PH3, and the pulverization during its solidification process. The experiments are carried out under different isothermal quenching temperatures and casting cooling rates. The results show that during the cooling process, the eutectic reaction occurs and produces the low‐ductility ζ phase, which leads to cracks in the microstructure and higher pulverization possibility. Moreover, sulfides and phosphides precipitate on the Fe‐Si microstructure and form clustered structures, and the release of PH3 increases with decreasing temperature. The internal stresses generate by phase transformations, the low‐ductility ζ phase, and the precipitation of sulfides and phosphides at crack sites collectively lead to the pulverization of FeSi75 alloy. It is also found that the grain size becomes smaller and more uniform at higher casting cooling rates, which effectively prevents the precipitation and enrichment of sulfides and phosphides, reduces PH3 release, and hence could prevent the pulverization of FeSi75 alloy. [ABSTRACT FROM AUTHOR]

A very fast, selective CO2 laser line scan direct synthesis method is presented and has been applied here to study phase and defect formation within an irradiated mixture of powdered oxides, as a proof‐of‐principle. A nominal composition interval of 0

Slag fuming (SF) is a metallurgical process designed to recycle Zn‐containing slags derived from various industrial residues. To protect the reactor from corrosive molten slag, a deliberate as‐solidified slag layer, known as a freeze lining (FL), is formed on the reactor walls using intense water‐cooled jackets. In this article, a computational‐fluid‐dynamics‐based model capable of simulating FL formation in a SF furnace is presented. To capture the complex multiphase flow dynamics, heat transfer, and FL formation during SF, a volume‐of‐fluid model is coupled with a mixture continuum solidification model. Three phases are considered: gas, liquid bulk slag, and solid slag (FL). Moreover, two types of FL are distinguished: one that solidifies on the reactor wall in the bulk slag region and another that solidifies on the reactor wall in the freeboard region owing to slag splashing. Comparisons between calculated FL thickness and heat fluxes and corresponding industrial data demonstrate satisfactory agreement. In this outcome, the robustness of the model is underscored and confidence in its accuracy is instilled. In the simulation results, valuable insights are provided into the evolution of the fuming process, particularly regarding the slag bath temperature, slag splashing dynamics, FL formation, local heat fluxes through the reactor wall, and global net energy balance. [ABSTRACT FROM AUTHOR]

Solid‐state electrolytes (SSEs) offer enhanced safety, extended cycle life, and increased energy density when replacing flammable liquid electrolytes in lithium‐ion batteries. Poly(ethylene oxide) (PEO)‐based SSE is the only candidate that has been commercially implemented in electric vehicles. However, the equipped battery needs to operate at temperatures above 50 °C, and its phase transitions at room temperature are still unclear. Herein, the solidification of the PEO‐lithium bis(trifluoromethanesulfonyl)imide (PEOn‐LiTFSI) system is revisited. Contrary to the prevailing view of forming PEO(6)‐LiTFSI spherulites, the presence of crystalline PEO(8)‐LiTFSI complexes is quantitatively confirmed. The nucleation and growth processes of crystalline PEO and PEO(8)‐LiTFSI spherulites are also visually elucidated, and phase transitions with the impedance change are correlated. In addition, it is demonstrated that the crystalline PEO shell surrounding the PEO(8)‐LiTFSI spherulites hinders the kinetics of crystal growth, thereby enabling the highest ionic conductivity at n = 10. Importantly, it is pointed out that instead of the poor ionic conductivity of the electrolyte layer, the heterogeneous nucleation of PEO(8)‐LiTFSI within the electrodes is the limiting factor in constructing room‐temperature all‐solid‐state batteries. [ABSTRACT FROM AUTHOR]

Based on the analysis of thermodynamic driving force and solidification kinetics under pressure, the influence mechanism of solidification pressure on columnar‐to‐equiaxed transition (CET) of high‐nitrogen steel is clarified. It is observed that increasing the solidification pressure from 0.5 to 2 MPa results in a shift of the CET positions toward the center. This is attributed to the fact that higher solidification pressure can promote the growth of columnar dendrites by increasing the solidification rate, temperature gradient, and cooling rate. Meanwhile, increasing the solidification pressure shortens the length of the diffusion zone ahead of the advancing columnar front and reduces the supercooling. As a result, it becomes more difficult for equiaxed dendrites to nucleate ahead of the advancing columnar front, leading to CET positions closer to the center. This indicates that the main influencing factor for the change in CET caused by changing solidification pressure is solidification kinetics, that is, changes in the nucleation and growth environment of equiaxed dendrites, while thermodynamic driving forces are not the primary factor causing CET position changes. [ABSTRACT FROM AUTHOR]

A very fast, selective CO2 laser line scan direct synthesis method is presented and has been applied here to study phase and defect formation within an irradiated mixture of powdered oxides, as a proof‐of‐principle. A nominal composition interval of 0

Solidification models are key during simulation of several industrial processes involving thermoplastics. For simplicity, crystallinity is often not considered within these models, despite it being responsible for the phase transition. Several advanced methods, which consider crystallinity as the onset of solidification have been proposed in literature however, these have primarily been applied to classical homopolymers such as polypropylene (PP). The focus of this study is to develop a model that can capture the rheological response observed during the transition from liquid‐like to solid‐like behavior in injection molding grade polyetheretherketone (PEEK) due to crystallinity. Isothermal rheological experiments are performed alongside dynamic scanning calorimetry (DSC) characterization to correlate relative crystallinity to the apparent increase in viscosity. The model is extended to nonisothermal processes through the incorporation of the Nakamura model. Nonisothermal crystallization rheology experiments are performed and compared with a simulation of the oscillating rheometer process for validation. The modeled viscosity response and crystallization half‐time reproduced the experimental data with sufficient accuracy at low cooling rates, with an error of less than 5% up to cooling rates of 20°C min−1. This shows that the method is an accurate means of obtaining the rheological response during crystallization in a numerical simulation. [ABSTRACT FROM AUTHOR]

This article presents an example of the joint use of a compressor heat pump that uses propane as a natural, ecological thermodynamic medium and a phase heat accumulator that uses paraffin as a medium. Special attention has been paid to the solidification process of the phase change material, and a simple theoretical model of the solidification of this material has been proposed. Thermodynamic balance calculations were carried out for the compressor heat pump and the phase heat accumulator. This paper presents a theoretical analysis of two examples of heating using a compressor heat pump, implementing the Linde cycle for the refrigerant R290 (propane): high-temperature heating at a temperature of 80 °C and low-temperature (surface) heating at a temperature of 60 °C, with the same unit heat output of 0.376 kW taken from the lower-temperature heat source of each evaporator. This heat is generated by the solidification of the PCM. The compressor power is 77 W in the first case and 40 W in the second. The energy efficiency coefficients of the compressor heat pump for the proposed combination of a phase heat accumulator and compressor heat pump are 5.98 and 10.40. The joint use of a heat accumulator and a heat pump presented in this paper can be used in applications for the heating of domestic water or water for space heating. [ABSTRACT FROM AUTHOR]

A Cu–Ni‐alloyed medium‐Mn duplex low‐density steel with a composition of Fe–9Mn–5.5Al–0.3C–3Ni–1.5Cu (wt%) is prepared by near‐rapid solidification. The microstructure features of the alloy under as‐cast, cold‐rolling, and heat treatments are studied. The effect of Cu‐ and Ni‐alloying elements on the microstructure and precipitates is discussed. In the results, it is shown that martensite and nanoscale precipitates are found in the microstructure of near‐rapid solidification. The enrichment of Cu is found at the phase boundaries of austenite and ferrite. A large number of annealing twins are present in the microstructure of cold‐rolled and annealed alloy. In the first principles and thermodynamic calculations, it is shown that Ni element is capable to shorten the nucleation incubation time of Cu precipitates. In addition, the interface segregation of Ni and Al elements reduces the adhesion work of Cu particles with the matrix. Both Cu and Ni elements increase the stacking fault energy of the alloy, which is increased from 37.3 to 44.2 mJ m−2. The contributions of precipitation strengthening and twinning strengthening to the strength of the alloy are 72 and 86 MPa, respectively, while the dominant contribution of dislocation hardening to the strength is 326 MPa. [ABSTRACT FROM AUTHOR]

Cellular stress and ageing involve an increase in crowding and aggregation of amylogenic proteins. We here investigate if crowding is the intrinsic cause of aggregation and utilise a previously established non-protein aggregation sensor, namely pseudoisocyanine chloride (PIC). PIC shows fibrillization in cells into a highly fluorescent J-aggregated state and is sensitive to crowding. Surprisingly, cell stress conditions stabilise the monomeric rather than the aggregated state of PIC both in the cytoplasm and in stress granules. Regarding the different physiochemical changes of the cytoplasm occurring upon cell stress, involving volume reduction, phase separation and solidification, the intrinsic crowding effect is not the key factor to drive associated self-assembly processes. Cellular stress and ageing involve an increase in crowding and aggregation of amylogenic proteins, but the connection between protein destabilisation and the onset of aggregation is poorly understood. Here, the authors utilize a non-protein aggregation sensor based on pseudoisocyanine chloride to analyse the effect of macromolecular crowding in the cytoplasm on the self-assembly process, and find that the high crowding densities observed in the cytoplasm and stress granules upon stress are not an intrinsic cause for aggregation of amylogenic proteins. [ABSTRACT FROM AUTHOR]

The surface‐wrinkled shrinkage structure of spheres is very common and also quite intriguing to explore and reveal the analogous droplet solidification kinetics in the space environment. Here, a liquid‐to‐solid phase transition experiment of floating refractory alloy droplets is designed to study the surface wrinkled shrinkage structures aboard China Space Station with a 10−5 gravity level. The experimental Ti‐Ni‐V alloy droplets undergo an extremely high overheating temperature beyond 1800 K and then achieve a supercooling of 307 K, displaying a strong thermodynamic metastability. The spherical surface deformation structures of this alloy under microgravity coupled with extreme metastable solidification are explored. Moreover, through the active control of metastable rapid solidification, a surface monophasic structure and a B2 structure capable of stress‐induced martensitic transformation are facilitated by wrinkled shrinkage dynamics under microgravity. Their findings shed further light on the surface deformation structures during the microgravity solidification process. [ABSTRACT FROM AUTHOR]

Thermal energy storage technologies have been widely used to mitigate intermittency from renewable energy sources such as solar energy. Phase change material (PCM) is a material that can be used as a heat storage medium and is available in a wide range of operating temperatures. Molten salt is one of the PCMs that has the advantage of a very high operating temperature. The PCM solidification simulation based on HitecXL molten salt using COMSOL Multiphysics software was carried out with variations in heat absorption of 1–5 kW/m2, assuming constant heat absorption. The results showed that the PCM solidification process started from the surface of the Stirling engine heat exchanger pipe. The part of the PCM that is solidified falls due to gravity, causing a phenomenon similar to a droplet. The flow that occurred was natural, driven by the buoyancy force resulting from density changes due to temperature gradients in the solidification process. The time required for the PCM to completely solidify was closely related to the amount of heat absorption; the greater the heat absorption from the pipe, the faster the PCM is fully solidified. [ABSTRACT FROM AUTHOR]

The present study numerically investigates the energy and exergy analysis of solidification of phase change materials within a double tube and triple tube latent heat storage unit using ANSYS Fluent. Double tube and triple tube thermal energy storage system's thermal characteristics are examined using MXene nano‐enhanced phase change material to determine system efficiency, discharged energy, heat transfer rate, exergy destruction, entropy generation number, exergetic efficiency, liquid fraction, solidification temperature contours. The result revealed that the double tube thermal energy storage with pure cetyl alcohol PCM has 14.76% lower discharge exergy than MXene‐based nano‐enhanced phase change material in pure solidification. In a triple tube thermal energy storage system, the solidification time for MXene‐based nano‐enhanced phase change material is impressively reduced by 54.76% compared to a double tube system using pure phase change material. At a Fourier number of 0.00672, MXene nano‐enhanced phase change material exhibits an 11.69% higher Stefan number (St) than cetyl alcohol phase change material in a double tube thermal energy storage system. At 2400 s, pure phase change material and MXene nano‐enhanced phase change material generated 3.14% and 4.88% less entropy than pure cetyl alcohol in the triple tube thermal energy storage system. During the pure solidification process in a double tube thermal energy storage system, pure cetyl alcohol experiences 7.60% higher exergy destruction compared to MXene nano‐enhanced phase change material at a solidification time of 2400 s. In a triple tube thermal energy storage system, the discharging temperature for pure cetyl alcohol phase change material is 2.92% lower than that in a double tube system. Double tube thermal energy storage with pure cetyl alcohol discharged more efficiently over 2400 s. The triple tube thermal energy storage system solidified cetyl alcohol PCM 20.83% faster than pure phase change material due to MXene nanoparticles' better thermophysical properties. Thus, MXene‐based nano‐enhanced cetyl alcohol phase change material solidifies faster per volume in a triple tube thermal energy storage latent heat system. [ABSTRACT FROM AUTHOR]

This paper presents a solar chimney that acts as a heat accumulator. It is based on its alternating charging (melting of the phase change material—PCM) and discharging (solidification), which helps to save energy and ensures stable operation of the solar chimney. In this paper, special attention has been paid to the heat dissipation process (solidification of the PCM). The theoretical model of solidification has been solved in an original way. This paper presents a new simple theoretical model for the solidification of the PCM on a flat plate and presents the results of numerical tests. The theoretical model presents a method for determining the heat transfer coefficient at the solidification front of the PCM. In addition, the heat transfer coefficient from the flowing air to the outer surface of the solidifying front plate was determined experimentally in an original way. The heat transfer coefficient values resulting from the experiments may be employed in order to calculate the heat transfer coefficient for air flowing through the slot of the collector in the solar chimney. The calculated value of the heat transfer coefficient was 18.55 W/m²K. [ABSTRACT FROM AUTHOR]

Alloy wheels must meet rigorous durability and safety tests to meet structural demand during use. The use of aluminum (Al) alloyed with silicon (Si) stands out due to the good relationship between density and strength and also its esthetic appeal, which is made possible by the suitable alloy machinability. The use of A356 alloy processed through low-pressure die casting and T6 heat treatment comes from the need for suitable mechanical properties and ease of large-scale cyclic processing. The wheel sector's high competitiveness demands accelerated development with less time-to-market and better performance. The use of numerical cast simulations helps predict the thermal and microstructural parameters of the alloy resulting from the solidification process inside a metallic mold. Understanding the solidification thermal parameters is of great importance for predicting either the phase morphologies or the dendritic length-scale of the casting, since these features have a direct impact on the alloy's strength. The present study aims to develop a computational simulation tool using commercial casting software to predict the tensile properties of as-cast and heat-treated automotive wheels. To achieve this objective, directional solidification (DS) experiments with the A356 alloy were carried out in order to determine equations relating the solidification time and cooling rate along the casting. The generated casting by the DS was further divided into parts, heat-treated and untreated, and each half part was examined for both tensile testing and the determination of secondary dendrite arm spacing (λ2). This allowed the development of key experimental equations relating λ2 with solidification time and tensile properties with λ2. In the end, a coupled simulation tool underwent testing using real tensile test data from wheels before and after T6 treatment. This testing involved two methods of correlating tensile properties with λ2: Hall-Petch-type (HP) and Ludvig model approaches. The HP model more accurately represents the strength data from various wheel regions, with a small average error of approximately 5.6% for ultimate strength. [ABSTRACT FROM AUTHOR]

The near-eutectic aluminum–nickel alloys are promising to be used for thermal management purpose because of their excellent thermal conductivity. However, owing to the solid solubility of nickel in aluminum lattice is small, the mechanical properties of these alloys can barely be promoted via the solid solution strengthening effect. The present study investigates the trace addition of silicon on the microstructure, rheology property, mechanical performance and thermal conductivity of the Al–5Ni alloy. Results show that the α-Al grains in the Al–5Ni alloy with trace silicon are significantly refined, and the fibrous Al3Ni phase is notably modified. It leads to a remarkable improvement of its mechanical properties. However, the mechanical properties and thermal conductivity are prominently decreased when the dosage of silicon excesses 0.3 wt%. The molten Al–5Ni alloy with relatively high silicon content possesses wider temperature range for flowing, indicating a sound fluidity of the melts, which is related to the solidification routes of the samples. This work provides a reference for the design of cast aluminum alloys with high strength and excellent thermal conductivity. [ABSTRACT FROM AUTHOR]

This study analyzes the effects of different pouring temperatures and mold temperatures on the crack behavior of NaCl–Na2SO4 composite water-soluble salt cores (WSSC). Firstly, calculate the solid fraction during the solidification process of the salt core using the Newton baseline method. Then predict the sensitivity of the salt core to thermal cracking using the cracking susceptibility coefficient model. Subsequently, the effects of different pouring temperatures and mold temperatures on the solidification and crack behavior of salt cores were compared. The results showed that when the pouring temperature was 800 °C and the mold temperature was 200 °C, the number of cracks significantly decreased, and the surface quality was the best. Finally, the microstructure and phase composition of WSSC were characterized using scanning electron microscopy. The results of this study indicate that increasing the mold temperature and selecting an appropriate pouring temperature can help improve the density of the salt core structure, reduce susceptibility of cracking, and enhance the surface quality of the salt core. [ABSTRACT FROM AUTHOR]

The quality of Al–Li castings is significantly influenced by fluidity and hot tearing susceptibility (HTS), underscoring the importance of comprehending castability and the related influencing mechanisms. Hence, this work systematically explores the synergistic effect of in situ TiB2 particles and Ti solute on fluidity and HTS of the Al–Li alloys. The addition of Ti solutes or in situ TiB2 particles yields a discernible improvement in both the fluidity and HTS of the Al–Li alloys. Furthermore, their combined addition further enhances fluidity and reduces HTS, resulting in a significant 67.3% enhancement and a remarkable 59.1% decrease, respectively. To elucidate these underlying influencing mechanisms, experimental results were compared with predictions derived from numerical simulation using ProCAST software, alongside assessments based on the CSC and Kou's criteria. Numerical simulations closely align with experimental results. However, the CSC criterion and Kou's criterion exhibit discrepancies when compared to experimental observations, highlighting their limitations in capturing the nuanced effects of minor Ti addition or TiB2 particles on fluidity and HTS. Therefore, a comprehensive exploration of other influencing factors, encompassing microstructural features, solidification interval, and diverse thermophysical parameters, was thoroughly examined to uncover the influencing mechanisms. These outcomes are poised to offer profound insights into the fluidity and HTS of Al–Li alloys, thereby advancing the utilization and progression of cast Al–Li alloy applications. [ABSTRACT FROM AUTHOR]

The precipitation process of inclusions in the high sulfur steel with the cerium addition is observed using the high‐temperature confocal scanning laser microscope (CSLM). Rare earth (Re) inclusions formed in the molten steel, and MnS inclusions precipitate along grain boundaries or on oxide cores at the end of solidification. With the addition of cerium, the average aspect ratio of inclusions in the steel decreases from 6.5 to 5.0, and the addition of cerium effectively modifies the elongated MnS. Thermodynamic calculations show the inclusion transformation during solidification, yet it lacked the formation of Ce2O2S and Re sulfides. According to the first‐principles calculation, the priority of the inclusion formation was Ce2O3 > CeAlO3, Ce2O2S > CeS > Ce3S4 > MnS. The stability of MnS inclusions is much lower than that of cerium‐containing inclusions. It is in situ observed that the addition of cerium promotes the formation of cerium‐containing inclusions and reduces the precipitation of MnS in the high sulfur steel. [ABSTRACT FROM AUTHOR]

In the present work, medical waste ash was used as an aluminosilicate precursor to produce a geopolymer binder with stabilised heavy metals. The ash was initially calcined at a temperature of 800 °C for two hours to reduce the organic content. Calcined kaolin and medical waste ash were used as precursors to produce the geopolymer binder and sodium silicate and calcium oxides were used as alkaline activators. The effect of curing temperature (23, 60, and 100 °C) and the calcium oxide addition (0, 5, and 10%) on the geopolymer properties were evaluated. Eighteen geopolymer samples were prepared and evaluated for immobilizing heavy metals through the Toxicity Characteristic Leaching Procedure (TCLP). When compared to raw materials, TCLP results indicated that geopolymerization can significantly reduce the concentration of heavy metals in the medical waste ash leachate. The metal fixation percentages of the geopolymers ranged from 70 to 100%. The sequential extraction test results showed that geopolymerization (stabilization/solidification) is very beneficial in reducing the bioavailable fraction in the solid waste and maximizing the difficulty of fraction extraction. [ABSTRACT FROM AUTHOR]

At present, in the directed energy deposition (DED) of metals, the heat transfer of the melt pool and microstructural evolution are not fully understood. This study investigates the thermal effect on the microstructure and the mechanical properties of DED AISI 316L, using in situ optical monitoring. Five thin-wall samples were tested to determine the effect on microstructural evolution and mechanical properties with variable laser powers and scanning speeds. A comprehensive optical monitoring system with a CMOS (coaxial complementary metal oxide semiconductor) visual module and an infrared camera was adopted in analyzing the temperature gradient and the solidification rate. The emissivity of the melt pool was calibrated, using the melt pool length, extracted from the coaxial visual image. The results showed that microstructures mainly consist of the coarse columnar grain and the equiaxed grain at the top layer of AISI 316L samples. The direction of epitaxial growth of columnar grains is affected by the compromise between directional heat flux and crystallographic direction. High numerical temperature gradient and high solidification rate are beneficial to obtaining fine grain size and high yield stress. A modified microstructure map for DED AISI316L was established, which correlates the solidification parameters with a solidification microstructure. This research study, combining temperature distribution, solidification parameter, microstructure, and tensile property, provides an experimental identification of solidification parameters and the model on the solidification theory for precision control of DED process. [ABSTRACT FROM AUTHOR]

In response to the challenges of poor engineering properties and the high difficulty in improving peat soil, a composite cement solidification agent (CCS) comprising ultra-fine cement (UFC) and ordinary Portland cement (OPC) was proposed for the solidification of simulated peat soil. The influence of UFC on the permeability of cement-soil samples was investigated through osmotic pressure tests and X-ray diffraction (XRD) experiments. Osmotic pressure tests results indicate that, under constant CCS dosage, the permeability coefficient k of specimens decreases with increasing UFC mass fraction, with a significant attenuation of the decreasing trend observed when the UFC mass fraction exceeds 12%. For CCS with a UFC mass fraction of 12%, k decreases with increasing CCS dosage, and the declining trend is notably attenuated when the dosage exceeds 25%. XRD results indicate that the diffraction peak intensity of calcium silicate hydrate (C-S-H) in the samples increases with both the increase in the UFC mass fraction and the curing time. Compared to OPC, CCS achieves superior solidification efficiency with a reduced cement dosage, facilitating the attainment of carbon reduction objectives. [ABSTRACT FROM AUTHOR]

New developments in nickel-based superalloys and production methods, such as the use of additive manufacturing (AM), can result in innovative designs for turbines. It is crucial to understand how the material behaves during the AM process to advance the industrial use of these techniques. An analytical model based on reaction–diffusion formalism is developed to better explain the solidification behavior of the material during laser metal deposition (LMD). The well-known Scheil–Gulliver theory has some drawbacks, such as the assumption of equilibrium at the solid–liquid interface, which is addressed by this method. The solidified fractions under the Scheil model and the pure equilibrium model are calculated using CALPHAD simulations. A differential scanning calorimeter is used to measure the heat flow during the solid–liquid phase transformation, the result of which is further converted to solidified fractions. The analytical model is compared with all the other models for validation. [ABSTRACT FROM AUTHOR]

The chemical composition of alloy 718 powder was optimized to suppress a solidification cracking in the additive manufactured part by the laser metal deposition method. The relationship between the condition of additive manufacturing and defects was evaluated. A lack of fusion was observed on the low heat input (low energy density), and the solidification cracking occurred on the high heat input (high energy density). The powder composition of alloy 718 was attempted to be optimized from a theoretical approach of the solidification cracking susceptibility. It was found that Si and B had a significant influence on the solidification cracking, therefore a preventive powder with reduced Si and B was developed. The effects of Si and B on solidification cracking were compared by reproducing the solidification conditions during additive manufacturing and evaluating the solidification brittle temperature range (BTR) using the Varestraint test. It was found that the BTR of the preventive material was smaller, and the solidification cracking susceptibility was improved. In addition, the solidification cracking did not occur in additive manufacturing using the preventive powder. In other words, it is suggested that the countermeasure for weld solidification cracking leads to the prevention of solidification cracking in additive manufacturing directly, and the effectiveness of the optimization of powder composition was verified. [ABSTRACT FROM AUTHOR]

Emulating the Ni-base superalloy γ + γ ′ microstructure in BCC–B2 refractory alloys is a promising design strategy to achieve high temperature strength and ductility. Ru-base B2 precipitates have shown exceptional thermal stability but can be difficult to solutionize, making high cooling rate solidification pathways like additive manufacturing (AM) a promising approach for synthesis of more homogeneous microstructures. Using single track laser experiments on aged bulk substrates, five representative refractory alloys with varying Ru-base B2 precipitates (AlRu, HfRu, TiRu) and matrix constituents (Mo, Nb) were investigated for their solidification behavior and defect susceptibility under laser melting conditions. Susceptibility to solidification cracking, solid-state cracking, and keyhole formation was found to be highly dependent on the matrix composition. Characterization of the melt pools by scanning and transmission electron microscopy shows evidence for disordered BCC upon solidification, enabling tailoring of the B2 precipitates that are thermodynamically stable above 1300 °C. The B2 precipitate morphologies in the melt tracks after aging treatments are influenced by the partitioning behavior of Ru from laser melting. Results from these single track experiments provide guidance toward design strategies for fabricable refractory BCC–B2 alloys. [ABSTRACT FROM AUTHOR]

As a typical metallurgical defect, macrosegregation seriously affects the internal quality of the continuous casting billet, and it cannot be solved by processes such as high-temperature diffusion and rolling. For continuous casting billet, the solidification shrinkage and thermal shrinkage of the microstructure directly affect the macrosegregation defect. In order to reveal the effects of solidification shrinkage and thermal shrinkage on the melt flow, microstructure distribution, and solute segregation, a multiphase solidification model based on the Eulerian–Eulerian approach was established in this work. The growth behaviors of the columnar dendrite trunk and the columnar dendrite tip were fully considered, as well as the nucleation, growth, free migration of equiaxed grains, and the columnar-to-equiaxed transition (CET). Besides, the corresponding relationship between the secondary dendrite arm spacing (SDAS) and the cooling rate has also been taken into account in the model, which makes the net mass transport source term of the mass conservation equations more accurate. The calculation results show that when no any shrinkage behavior is considered in the model, the melt flow velocity in front of the solidification end will gradually decrease until it is the same as the casting speed, and the segregation index at the billet center will gradually increase until it reaches the maximum value at the solidification end. Both thermal shrinkage and solidification shrinkage can generate a negative pressure zone in the billet center, sucking the poor-solute melt located the upstream of continuous casting strand flows towards the solidification end, and mixing with the enriched-solute melt before the solidification end, thereby inhibiting macrosegregation. However, compared with the solidification shrinkage, the effect of thermal shrinkage on reducing the positive segregation index in the billet center is limited. [ABSTRACT FROM AUTHOR]

In this study, we simulated the solidification behavior, microsegregation, and heat treatment in Fe–xMn–7.5Al–5Cr–1.0C lightweight steels using the CALculation of PHAse Diagrams method. The solidification paths and microsegregation of these steels were calculated with the Scheil-Gulliver model and equilibrium calculator in the Thermo-Calc® software. At the same time, thermodynamic calculations predicted heat-treatment temperatures for different steels. The transformation path of the Fe–xMn–7.5Al–5Cr–1.0C (x = 18 and 20 wt.%) lightweight steels is as following: liquid → liquid + δ-ferrite → δ-ferrite + γ-austenite → γ-austenite → γ-austenite + M7C3, according to equilibrium and Scheil's calculations. In case of 25 wt.% Mn steel, the two-phase region of δ-ferrite and γ-austenite is absent in the transition path. The segregation behaviour of solute elements in the liquid, ferrite, and austenite phases were predicted using the Scheil model. The heat treatment temperature for single-phase formation is expected to be between 900 °C and 1030 °C. [ABSTRACT FROM AUTHOR]

The utilization of uniformly deposited metal droplets has attracted significant attention for diverse applications, such as rapid prototyping and manufacturing. Achieving flawless aluminum structures through droplet-based liquid metal 3D printing (LM3DP) is critical in aerospace and electronics. However, challenges persist in eliminating defects during deposition due to constrained temperature ranges and complex impact dynamics. This study introduces a 3D computational model using a volume of fluid technique to analyze the consecutive deposition of molten aluminum droplets on a heated substrate, protected by nitrogen gas. Simulations reproduce droplet shapes in agreement with experimental results. Molten aluminum droplets solidify layer by layer continuously in an upward direction due to high thermal conductivity, forming surface ripples. L-shaped ripples emerge on neighboring droplets due to combined effects of solidification and oscillation, which involve alternating spreading and recoiling of the droplets leading to defects like cold laps, whereas bottom-hole defects occur due to inadequate metal filling with the substrate. This investigation systematically explores shape, defect formation, temperature, solid fraction, and velocity evolution during continuous deposition. Insights establish a fundamental basis for LM3DP technology. [ABSTRACT FROM AUTHOR]

In injection molding, heat transfer at the polymer/mold interface during solidification of the polymer significantly affects the cooling rate, microstructure, and hence the product quality. An accurate estimation of the boundary heat flux transients is essential for the successful simulation of polymer solidification, which can aid in predicting and preventing potential defects that may arise from improper filling and cooling. Simulation studies also help in optimizing the cycle time with different process parameters. In the present work, a pneumatically-operated injection molding machine capable of producing a single component in one cycle was designed and fabricated in-house to estimate the heat flux transients at the polymer/mold interface. The mold used for solidification of the polymer was made from tool steel (P20) with a simple rectangular cavity. The mold was instrumented with thermocouples across the thickness to record its thermal history during injection molding. The polymer/mold interfacial heat flux transients were estimated by solving an inverse heat conduction problem (IHCP). The temperature measured at locations beneath the cavity surface inside the mold was used as an input to the inverse solver. Altering the melt injection and mold temperatures showed negligible effects on heat flux transients at the polymer/mold interface. The estimated solidification time for the polymer sample was about 2 s. [ABSTRACT FROM AUTHOR]

Iron-rich intermetallics in Al-Si alloys pose a major challenge in aluminum recycling. Virgin Al-Si alloys typically contain a minimal iron concentration which enhances properties like tensile strength and conductivity. Although aluminum is a recycling friendly metal, Fe impurity increases due to scrap contaminations, coatings and rust, which eventually leads to the evolution and growth of detrimental Fe-rich intermetallics. These Fe-rich particles exhibit platelet or needle-like morphologies, and their aspect ratios grow with higher Si and Fe concentrations. Among the identified β phases, β-Al5FeSi is predominantly known for its fragility and negative impact on the mechanical properties of the alloy. Two potential solutions to this problem are, removing Fe from Al-Si alloys or suppressing the formation of β-Al5FeSi. While the method of alloying additions is much more viable for industry scale. Current study is a critical review of morphological modification of Fe-rich intermetallics through alloying additions to Al-Si alloys. The independent mechanism(s) of suppression of β-Al5FeSi phase by Mn, Mo, V and Cr additions is discussed along with the challenges and future scope of this work are discussed in detail. [ABSTRACT FROM AUTHOR]

Additive manufacturing (AM) provides an alternate and efficient route for producing intricate geometries, such as turbine blades in the high-pressure compression stages of an aero-engine. Herein, we present a multi-scale modeling approach involving the simulation of the laser-based directed energy deposition (L-DED) process and the resulting microstructure evolution to identify the process parameters for producing defect-free directionally solidified (DS)/single-crystalline (SX) Ni-based superalloy components. Notably, our approach involves a novel process model formulated in a diffuse-interface framework in contrast to the volume of fluid (VoF) and level-set methods documented in the literature. The temperature history obtained from the process simulations serves as an input for a Monte Carlo-based solidification microstructure model, which predicts the feasibility of epitaxial growth for a given set of process parameters. A parametric study is conducted using the above models by varying the laser power and scanning velocity to obtain an optimal processing window for epitaxial growth, which is validated experimentally. The study reveals that higher laser power and scanning velocities lead to epitaxial growth. [ABSTRACT FROM AUTHOR]

In this work, the effect of Nb addition on the evolution of Fe-rich intermetallics in Al–Si–Fe-type alloy has been investigated through melting and casting method. Electron microscopy (SEM) has revealed that Nb behaves distinctly in the Al–Si–Fe alloy, when it is added in the form of Al–10Nb master alloy compared to the same added in the form of elemental powder. Results indicate that some Nb atoms, together with Al–Si–Fe, form a quaternary, Al8(FeNb)Si-type intermetallic phase, in the elemental Nb powder inoculated Al–Si–Fe alloy. In contrast, no such phases were observed when Nb was added to Al–Si–Fe melt in the form of Al–10Nb master alloy. The possible phase evolutions mechanisms have been discussed herein. Figures 1c and 2a, respectively, represent the SEM–EDS elemental mapping of Al3Nb particles found in the as-cast Al–Si–Fe alloy inoculated with Al–10Nb master alloy, while Figs. 1d and 2b show the SEM–EDS elemental mapping of Al3(FeNb)Si particles found in the as-cast Al–Si–Fe alloy inoculated with elemental Nb powder. Results show that Al3(FeNb)Si particles are absent in the as-cast Al–Si–Fe alloy inoculated with Al–10Nb master alloy. [ABSTRACT FROM AUTHOR]