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Realizing improved strength–ductility synergy in eutectic alloys acting as in situ composite materials remains a challenge in conventional eutectic systems, which is why eutectic high-entropy alloys (EHEAs), a newly-emerging multi-principal-element eutectic category, may offer wider in situ composite possibilities. Here, we use an AlCoCrFeNi 2.1 EHEA to engineer an ultrafine-grained duplex microstructure that deliberately inherits its composite lamellar nature by tailored thermo-mechanical processing to achieve property combinations which are not accessible to previously-reported reinforcement methodologies. The as-prepared samples exhibit hierarchically-structural heterogeneity due to phase decomposition, and the improved mechanical response during deformation is attributed to both a two-hierarchical constraint effect and a self-generated microcrack-arresting mechanism. This work provides a pathway for strengthening eutectic alloys and widens the design toolbox for high-performance materials based upon EHEAs. Producing in situ composite materials with superior strength and ductility has long been a challenge. Here, the authors use lamellar microstructure inherited from casting, rolling, and annealing to produce an ultrafine duplex eutectic high entropy alloy with outstanding properties.

The precision casting of nickel-based single-crystal superalloys imposes stringent requirements on the high-temperature stability and chemical inertness of ceramic shell face coats. To address the issue of traditional EC95 shells (95% Al2O3–5% SiO2) being prone to react with the alloy melt at elevated temperatures, thereby inducing casting defects, this study proposes a lanthanide oxide-based ceramic face coat material. Three distinct powders—LaAlO3 (LA), LaAlO3/La2Si2O7 (LAS), and LaAl11O18/La2Si2O7/Al2O3 (LA11S)—are successfully prepared through solid-phase sintering of the La2O3-Al2O3-SiO2 ternary system. Their slurry properties, shell sintering processes, and high-temperature performance are systematically investigated. The results demonstrate that optimal slurry coating effectiveness is achieved when LA powder is processed with a liquid-to-powder ratio of 3:1 and a particle size of 300 mesh. While LA shells show no cracking at 1300 °C, their face coats fail above 1400 °C due to the formation of a La2Si2O7 phase. In contrast, LAS and LA11S shells suppress cracking through the La2Si2O7 and LaAl11O18 phases, respectively, exhibiting exceptionally high-temperature stability at 1400 °C and 1500 °C. All three shells meet the high-temperature strength requirements for CMSX-4 single-crystal alloy casting. Interfacial reaction analysis and Gibbs free energy calculations reveal that Al2O3-forming reactions occur between the novel shells and alloy melt, accompanied by minor dissolution erosion without other chemical side reactions. This work provides a high-performance face coat material solution for investment casting of nickel-based superalloys.

The improvement of the creep properties of single-crystal superalloys is always strongly motivated by the vast growing demand from the aviation, aerospace, and gas engine. In this study, a static magnetic-field-assisted solidification process significantly improves the creep life of single-crystal superalloys. The mechanism originates from an increase in the composition homogeneity on the multiscales, which further decreases the lattice misfit of γ/γ′ phases and affects the phase precipitation. The phase-precipitation change is reflected as the decrease in the γ′ size and the contents of carbides and γ/γ′ eutectic, which can be further verified by the variation of the cracks number and raft thickness near the fracture surface. The variation of element partition decreases the dislocation quantity within the γ/γ′ phases of the samples during the crept deformation. Though the magnetic field in the study destroys the single-crystal integrity, it does not offset the benefits from the compositional homogeneity. The proposed means shows a great potential application in industry owing to its easy implement. The uncovered mechanism provides a guideline for controlling microstructures and mechanical properties of alloys with multiple components and multiple phases using a magnetic field.

Purpose To compare intramedullary nailing (IMN; suprapatellar, infrapatellar, or parapatellar) with minimally invasive plate osteosynthesis (MIPO) for proximal tibial fractures by systematically evaluating clinical outcomes. Materials and methods We included English-language randomized controlled trials (RCTs) and comparative studies evaluating adult proximal tibial fractures (AO/OTA 41-A2/A3, 41-C1/C2) treated with IMN or MIPO. Databases including PubMed, Embase, Cochrane, and Scopus were searched until June 9, 2025. Study selection, data extraction, and quality assessment were independently performed by two reviewers. Statistical analyses were conducted using STATA version 18.0. Dichotomous outcomes were expressed as risk ratios (RR) or odds ratios (OR), and continuous outcomes as weighted mean differences (WMD) or standardized mean differences (SMD), each with 95% confidence intervals (CI). Heterogeneity was assessed using I² statistic and Cochran’s Q test, applying a random-effects model if I² >50% or p  < 0.1. Publication bias was evaluated via funnel plots and Egger’s regression test. Results Eleven studies comprising 829 patients (409 IMN; 420 MIPO) met the inclusion criteria. The IMN group demonstrated a significantly lower infection rate compared with the MIPO group (RR = 0.55; 95% CI, 0.33–0.91; p  = 0.019). Conversely, traditional (infrapatellar and parapatellar) IMN approaches showed significantly increased anterior knee pain incidence compared to MIPO (RR = 6.27; 95% CI, 0.92–20.55; p  = 0.002). Suprapatellar IMN studies did not report anterior knee pain outcomes. No significant differences were identified between IMN and MIPO in nonunion rates (RR = 1.04; 95% CI, 0.61–1.77; p  = 0.88), malalignment incidence (RR = 1.29; 95% CI, 0.88–1.89; p  = 0.19), knee range of motion (WMD = 0.08; 95% CI, -2.22–2.37; p  = 0.95), or implant removal rates (RR = 0.69; 95% CI, 0.41–1.15; p  = 0.16). Conclusion IMN fixation for proximal tibial fractures significantly reduces infection risk compared with MIPO surgery, but traditional IMN approaches (infrapatellar/parapatellar) carry a greater risk of anterior knee pain. No differences were observed in nonunion rates, malalignment, knee range of motion, or implant removal rates between the two treatments. Further high-quality studies evaluating suprapatellar IMN approaches are warranted.

Wetting transitions between molten metals and different solid substrates were investigated using the sessile drop method to evaluate the possibilities of regulating wettability by high magnetic fields (HMFs) during wetting. For most wetting counterparts, the molten-metal droplet outline showed an apparent change because of the influence of HMFs. Contact angles that were measured with HMFs decreased compared with contact angles that were measured without HMFs. The temperature and magnetic-flux density had an evident but more complicated effect on the wetting transition. For reactive wetting systems, the effect of HMFs on changes of element distributions at the metal/substrate interface may lead to a variety of wetting transitions. For non-reactive wetting systems, solidified metal droplets can move from the solid substrates after wetting. No detailed and comprehensive explanations on HMF wetting-transition mechanisms exist, and further work is required. This study contributes to perfect wetting mechanisms and theories and provides a scientific approach to control wettability.

The transformation of liquid–solid interface induced by the steady magnetic field (SMF) in the directionally solidified Ni-10 wt pct Cr alloy was studied experimentally. At the moderate pulling rate (50 μm s−1), it could be observed that the interface morphology gradually transformed from planar to cellular shape with increasing the SMF intensity (0 T, 3 T, 6 T). However, the cellular interface at the high pulling rate (100 μm s−1) was not influenced by the SMF. 3D numerical simulations suggested that the transformation of interface morphology originated from the thermoelectric magnetic convection near the wavelike interface at the early stage of solidification. From the composition measurement, it was found that the formation of microsegregation at the moderate pulling rate was associated with the interface morphology. Under the 3 T SMF, the liquid–solid interface remained planar and the microsegregation level increased in comparison with that without the SMF. Under the 6 T SMF, the liquid–solid interface became cellular and the microsegregation level was reduced. The factors affecting microsegregation were evaluated. The effective partition coefficient was estimated based on composition data. It was revealed that the effective partition coefficient increased with the 6 T SMF due to the thermoelectric magnetic and magnetic damping effects within the cellular structure. Additionally, the solid diffusivity was measured using the diffusion couple technique. It was found that the interdiffusion coefficient of Cr decreased with increasing the SMF intensity. The modified Brody model was used to predict the microsegregation behavior in the SMF. The predicted results were in agreement with experimental observation. It could be concluded that the decrease in solid diffusivity enhanced the formation of microsegregation for the planar interface, whereas the increase in effective partition coefficient in the SMF was beneficial for alleviating the extent of microsegregation for the cellular interface.

Solidification of Al-Cu alloys has been investigated using a 29 Tesla super high static magnetic field (SHSMF). The results show that, by imposing a 29 Tesla SHSMF, the size of primary phases and spacing of eutectic structure have been refined through the increase of undercooling which results from the suppression of diffusion coefficient. The diffusion coefficient of atoms in the liquid matrix decreases to be about 1.2 × 10 −12  m 2 /s. The lattice constants are reduced and high dislocation density forms in the primary phase, which induces a solute trapping effects. The spacing of (110) plane in Al 2 Cu is corrected to be 4.3123 Å and 4.2628 Å for Al-40  wt .%Cu alloys treated without and with a SHSMF. The spacing of (111) plane in Al is corrected to be 2.3351 Å and 2.3258 Å for Al-26  wt .%Cu alloys treated without and with a SHSMF. The compression yield strength has been improved by about 42% from 268 MPa to 462 MPa for Al-26  wt .%Cu and 42.5% from 248 MPa to 431 MPa for Al-40  wt .%Cu. The maximum elastic strain increases from about 2% to 4.3% for Al-26  wt .%Cu and from 2% to 4% for Al-40  wt .%Cu. It is expected that SHSMF is beneficial to process materials with high mechanical properties.

Understanding how the magnetic fields affect the formation of reinforced phase during solidification is crucial to tailor the structure and therefor the performance of metal matrix in situ composites. In this study, a hypereutectic Al-40 wt.%Cu alloy has been directionally solidified under various axial magnetic fields and the morphology of Al 2 Cu phase was quantified in 3D by means of high resolution synchrotron X-ray tomography. With rising magnetic fields, both increase of Al 2 Cu phase’s total volume and decrease of each column’s transverse section area were found. These results respectively indicate the growth enhancement and refinement of the primary Al 2 Cu phase in the magnetic field assisting directional solidification. The thermoelectric magnetic forces (TEMF) causing torque and dislocation multiplication in the faceted primary phases were thought dedicate to respectively the refinement and growth enhancement. To verify this, a real structure based 3D simulation of TEMF in Al 2 Cu column was carried out and the dislocations in the Al 2 Cu phase obtained without and with a 10T high magnetic field were analysed by the transmission electron microscope.

Understanding the macrosegregation formed by applying magnetic fields is of high commercial importance. This work investigates how static magnetic fields control the solute and primary phase distributions in four directionally solidified alloys (i.e., Al-Cu, Al-Si, Al-Ni and Zn-Cu alloys). Experimental results demonstrate that significant axial macrosegregation of the solute and primary phases (i.e., Al 2 Cu, Si, Al 3 Ni and Zn 5 Cu phases) occurs at the initial solidification stage of the samples. This finding is accompanied by two interface transitions in the mushy zone: quasi planar → sloping → quasi planar. The amplitude of the macrosegregation of the primary phases under the magnetic field is related to the magnetic field intensity, temperature gradient and growth speed. The corresponding numerical simulations present a unidirectional thermoelectric (TE) magnetic convection pattern in the mushy zone as a consequence of the interaction between the magnetic field and TE current. Furthermore, a model is proposed to explain the peculiar macrosegregation phenomenon by considering the effect of the forced TE magnetic convection on the solute distribution. The present study not only offers a new approach to control the solute distribution by applying a static magnetic field but also facilitates the understanding of crystal growth in the solute that is controlled by the static magnetic field during directional solidification.

The solute migration behavior in the mushy zone of an Al-18 at. pct Ni alloy under a high magnetic field was investigated experimentally. Quenching experiments were carried out under different magnetic fields after thermal stabilization. Directional solidification experiments were conducted to explore the precipitation mechanism. A high magnetic field affected the solute migration in the mushy zone significantly. When exposed to a magnetic field, the original cellular-like peritectic Al3Ni changed into an irregular block shape, with many precipitated small dendritic Al3Ni phases, which have not been observed previously. Directional solidification experiments proved that the dendrite phase precipitated during quenching. The application of a magnetic field resulted in the original straight and clear peritectic interfaces becoming uneven and rugged. A coupling of Lorentz, thermoelectromagnetic, and magnetic forces was proposed to explain solute migration in the mushy zone. This coupling hindered the original solute transport behavior and crystal growth mechanism, induced melting and solidification along the transverse direction, and produced many Ni-rich droplets and concentrated Ni atoms at the peritectic interface during thermal stabilization. This study enriches the influence mechanism of high magnetic fields on the solidification of peritectic alloys and provides the possibility for further microstructure and alloy property regulation.