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An investigation on oscillating characteristic of free surface in a liquid bridge for high Pr number fluids under gravity has been conducted numerically. Against the former studies, free surface is treated as a deformable surface in the direct numerical simulation (DNS) of liquid bridge by using a mass conserving level set method for the first time. The results show that, the moving track of vortex centers appears the shape of axisymmetric hook in the stable stage of thermocapillary convection, and the fluctuation of surface velocity is closely relative to the motion of cell flow toward the center and cold disk. In the process of transforming from the stable stage to oscillatory stage, the moving track of vortex centers of cell flow shows the asymmetry and step characteristic. The coupling effects of the temperature, velocity and free surface oscillations constitute complete mechanism of thermocapillary convection oscillations. The temperature firstly oscillates at the hot corner, and transfer direction of temperature oscillation is from the hot corner to inner. The velocity of surface flow is larger than that of internal flow, and the surface flow is supplied by the bulk return flow with the disturbance information of the velocity. The velocity oscillation lags behind the temperature oscillation at the hot corner. The closer to the intermediate height, the larger amplitudes of temperature and velocity are. The oscillation law of velocity and free surface at the intermediate height are the same, and there are two obvious oscillation bifurcations. [ABSTRACT FROM AUTHOR]

[Display omitted] Segmenting casting defect regions is vital for assessing defect levels in casting products. In complex backgrounds with multi-scale defects and regions of fuzzy and weak texture, existing methods often fail to capture detailed features of the defect, leading to incomplete segmentation. This study developed a casting defect region segmentation method based on a dual–channel encoding–fusion decoding (DCE–FD) network. Initially, an encoding network module based on a deep and shallow dual–channel structure (ENM–DSDCS) was established to extract macroscopic and multi-scale detail features using deep and shallow structure networks, respectively. This approach ensures comprehensive feature extraction from multi-scale fuzzy and weak texture defect areas. Further, a decoding network module based on attention-based bidirectional guidance fusion (DNM–ABGF) was developed. This module guides the semantic and multi-scale detail branch features to achieve complementary information fusion at each scale level during the decoding stage, thereby preserving fuzzy boundaries and other details in the fusion process and enhancing the accuracy and integrity of segmentation. Experimental results demonstrate that the mean intersection over union (mIOU) and Dice coefficients for defect region segmentation in radiographic images of castings were 92% and 75.71%, respectively. These metrics surpass those of eight advanced segmentation methods in terms of accuracy and consistency. The proposed method significantly improves sensitivity to feature detail and accurately segments potential fuzzy regions of multi-scale defects, offering promising advancements in the nondestructive testing of casting products. [ABSTRACT FROM AUTHOR]

Abstract: This paper presents a rigorous proof of existence and uniqueness of solutions to laminar boundary layer flow in power law non-Newtonian fluid. A theoretical estimate for skin friction coefficient is given, which is characterized by a power law exponent. The reliability and efficiency of the proposed estimate formula are verified by numerical results with a good agreement. The estimate formula can be successfully applied to give the value of the skin friction coefficient. [Copyright &y& Elsevier]

Suitable similarity transformations were used for reducing the generalized N-diffusion equations to a class of singular nonlinear boundary value problems. Similarity solutions are presented analytically and numerically. The results indicated that for each fixed α, the general diffusion flux θ(s) decreases with the increase of the power law N and sharply with the increase of σ. For 0<σ&les;1, θ(s) decrease with the increase of α, however, the behavior is quite opposite for σ>1. [Copyright &y& Elsevier]

Sinter-HIP combining vacuum and pressure in one-step sintering process has been applied to prepare ultrafine crystalline cemented carbide with a surface gradient layer enriched in binder. The effect of powder particle size on gradient formation and grain growth has been examined. The results show that the gradient layer thickness increases with decreasing WC and Ti(C,N) powder particle size. The number of abnormal WC grains increases with decreasing WC powder particle size. The formational mechanism of the gradient cemented carbide with ultrafine grains is discussed through analyzing the decomposability of nanoscale Ti(C,N), atomic diffusion and grain growth during one-step Sinter-HIP process. [ABSTRACT FROM AUTHOR]

Ultrafine crystalline functionally graded cemented carbides (FGCCs) with a surface zone enriched in binder phase were prepared by a one-step Sinter-HIP method. The influence of sintering pressure and cubic carbide composition on the formation of gradient layer was examined. The results show that the ultrafine FGCC with surface zone enriched in binder phase can be formed by the one-step Sinter-HIP method. The process of the gradient layer formation is accelerated under higher sintering pressure; the gradient layer thickness increases with the sintering pressure increasing. The gradient layer thickness is controlled by diffusion distance of cubic carbide formers, such as Ti, Ta and Nb. The addition of (Ta,Nb)C leads to decrease the thickness of gradient layer. [ABSTRACT FROM AUTHOR]

In this study we have explored how a high magnetic field (HMF) affects the structure and magnetic properties of Fe thin films fabricated on Si (100) substrates at various substrate temperatures by using a thermal evaporation method. At a substrate temperature of room temperature (RT), the HMF increased the width of column and the formation energy of the films. This behavior occurred because the HMF induced an excess energy-Zeeman energy which is larger than the sum of the kinetic energy and thermal energy of Fe without the HMF. This increased the particle size and decreased the roughness of the film deposited at RT and 6 T. When the substrate temperature was increased to 400 °C, the growth mode is changed from columnar (RT) to layered (400 °C). The HMF increased the grain size. The film deposited at RT and 6 T had much improved soft magnetic properties from its modified microstructure. While thermal disturbances decreased the effect of HMF on the magnetic properties of the film deposited at 400 °C. In particular, the influence of HMF on the microstructure and magnetic properties of Fe films is significant not in the evaporation stage but in the condensation process of film. [ABSTRACT FROM AUTHOR]

The influence of interdiffusion on the magnetic properties of Co/Si (100) films after thermal annealing in the presence of a strong magnetic field was investigated. The interdiffusion coefficients of films that were annealed at temperatures of 380 °C and 420 °C in the presence of high magnetic fields were not affected. However, the interdiffusion coefficient of films annealed at 400 °C in the presence of a high magnetic field decreased significantly. The change in the interdiffusion coefficient, caused by high magnetic field annealing, increased the content of the magnetic phase. This increase in the magnetic phase improved the saturation magnetization. A new method of high magnetic field annealing is presented that can modulate the diffusion and magnetic properties of thin films. [ABSTRACT FROM AUTHOR]

The effects of high magnetic field annealing on the inter-diffusion behavior of Co/Si (100) films were investigated using diffusion couple technique. Significant Co and Si inter-diffusion was verified by X-ray photoelectron spectroscopy. The inter-diffusion coefficients of thin-film/semiconductor were calculated. Compared to the no-field case, the inter-diffusion coefficients clearly increased when a high magnetic field of 11.5 T was applied at 300 °C, 350 °C, 450 °C and 500 °C. This effect can be attributed to an increase in the chemical potential gradient induced by magnetic free energy in a high magnetic field. For the samples at 400 °C, the inter-diffusion coefficients decreased when a high magnetic field of 11.5 T was applied. The phenomenon may due to the structure transformation caused by a high magnetic field. [ABSTRACT FROM AUTHOR]

Abstract: The effect of a high magnetic field on phase formation and determination in Ni–Fe film at nanoscale is reported. The bcc structure of the film changed to the coexistence of bcc and fcc phases by increasing the substrate temperature from 25 to 200 to 400 °C without magnetic field. Under a 6 T magnetic field, a coexistence of bcc and fcc phases was formed whatever structures the films prepared without magnetic field are. Furthermore, each nanograin exhibited only a single phase. The effect of high magnetic field indicates that the reduction in the Gibbs free energy (entropy) for the fcc phase by the high magnetic field is larger than that for the bcc phase. Furthermore, the reduction is different for various substrate temperatures. The results indicate that the phase formation is tunable at the nanoscale under high magnetic field. [Copyright &y& Elsevier]

Abstract: We report on the influence of magnetic field strength on the alloy Tb0.27Dy0.73Fe1.95 during slow-cooling solidification. We examined the effect of magnetic field strength on microstructure, magnetization, and magnetostrictive properties of this giant magnetostrictive alloy. We found that after field-treated solidification, the microstructure of specimens had a distinct grain arrangement and displayed magnetic anisotropy. The crystal orientation changed from random in the field-free treatment to aligned along the 〈110〉 direction in flux densities of 1 and 2.2T, and along the easy magnetization axis 〈111〉 at a flux density of 4.4T. In consequence, the magnetostrictive coefficient of the samples under various stresses improved with increasing magnetic flux density. Both the d 33 and k 33 values and the energy transformation efficiency of the field-treated specimens showed strong enhancements. [Copyright &y& Elsevier]

Highlights: [•] We present the change of the crystal orientation and magnetostriction of TbFe2 based alloy during treatment in the semi-solid state in high magnetic fields. [•] Orientation of the TbFe2 phase undergoes a transformation of 〈113〉 to 〈111〉 to 〈110〉 with increasing magnetic flux density. [•] Magnetostrictive property is slightly lowered at 4.4T, but strongly enhanced at 8.8T and 11.5T. [ABSTRACT FROM AUTHOR]

Abstract: Isothermal heat treatment experiments of an Al–4.8mass%Cu alloy were carried out under different magnetic field intensities, at different temperatures and for different holding times. The influence of high magnetic fields on area fraction of θ phase in the solidified microstructure was investigated. It was found that the area fraction of the θ phase was lower when imposing the magnetic field compared to samples heat-treated without magnetic field. In other words, the magnetic field accelerated the phase transformation to the equilibrium state. In addition, the area fraction of the θ phase was independent of magnetic field intensity. This effect of high magnetic fields on the decreasing of the θ phase was discussed from the viewpoint of the effect of high magnetic fields on diffusion. [Copyright &y& Elsevier]

Abstract: Nanocrystalline Fe x Ni1−x (in at%, x=0.74, 0.6, 0.55, and 0.3) thin films were prepared on a 25°C quartz substrate by using a molecular beam vapor deposition method with and without a 6T magnetic field. The microstructure of the thin films was characterized by energy dispersive x-ray spectroscopy, x-ray diffractometry and transmission electron microscopy. The magnetic and electrical properties of the thin films were examined by a vibrating sample magnetometer and four-point probe method. Results show that the thicknesses of these films with different compositions are 50, 90, 80, and 150nm, correspondingly. The crystallinity of Fe x Ni1−x (x=0.74 and 0.6) thin films is enhanced, and the γ 〈111〉 orientation degree of the Fe x Ni1−x (x=0.55 and 0.3) thin films increases under a 6T magnetic field. The grain refinement and defect decrease under 6T magnetic field are affirmed by TEM. A 6T magnetic field can help the thin films transform from anisotropy to isotropy. The soft magnetic properties of the Fe x Ni1−x (x=0.74, 0.6, 0.55, and 0.3) thin films are enhanced, and their resistivities decrease under a 6T magnetic field. [Copyright &y& Elsevier]

Abstract: The effects of high magnetic fields on the migration and rotation of TiAl3 particles in an Al–7wt.% Si alloy were studied. Without magnetic fields, the rod-like TiAl3 particles segregate at the lower part of the solidified structure. Under high uniform magnetic fields, these particles rotate to an orientation with their longitudinal axes parallel to the direction of the magnetic flux. The segregation of the particles reduces with the increase of the magnetic flux density. A negative gradient field enhances the effect of the uniform magnetic field. By altering high magnetic fields, Al–Si alloy samples containing homogeneously distributed and preferably aligned TiAl3 particles were prepared. [Copyright &y& Elsevier]

Abstract: Solidification experiments of aluminum–nickel binary alloys under uniform high magnetic fields have been conducted. The effects of high magnetic fields on the crystal orientation of Al3Ni were investigated by XRD and the alignment of primary phases Al3Ni were also analyzed. Experimental results showed that the easy magnetization axis of Al3Ni crystal oriented parallel to the imposed magnetic fields and the primary phase Al3Ni aligned perpendicular to the magnetic fields. Magnetic orientation of crystal was determined by magnetic anisotropy energy. Whereas the phase alignment should be contributed to the combined effects of magnetic orientation, crystal growth and the effects of magnetic fields on mass transport during solidification. [Copyright &y& Elsevier]

MnSb/Sb–MnSb functionally graded material (FGM) has been successfully fabricated using a semi-solid forming process under magnetic field gradients. Mn–Sb alloy with a hypoeutectic composition was used to produce particle-dispersed composites. The graded composition of MnSb particles could be controlled by adjusting the BdB/dz value of the field gradient and the holding time. The direction along which the volume fraction of the particles increased could also be controlled artificially by adjusting the field gradient direction. [Copyright &y& Elsevier]

Bulk layered synthetic Mn–Sb composites, with a gradient structure in morphology and composition towards the surfaces, were fabricated directly in situ under high magnetic field gradient conditions. Both of the primary phases of Mn–Sb binary system, i.e. MnSb and Sb, were found to segregate simultaneously from desired domains with a gradient interface in morphology in those alloys with hypo-eutectic composition. The volume fraction of the segregated phases strongly depended on the product of the magnetic flux density and its gradient. [Copyright &y& Elsevier]