With the strategic shift toward reducing reliance on critical raw materials, Cobalt-free eutectic high-entropy alloys (EHEAs) have emerged as a pivotal frontier for high-performance structural applications. This review systematically elucidates the synergistic relationship between Co-free alloy design and the non-equilibrium solidification mechanisms of Selective Laser Melting (SLM). The ultra-high cooling rates (105-108 K/s) inherent in SLM are shown to refine eutectic lamellae to the sub-micron scale (typically <300 nm), effectively suppressing the macro-segregation common in conventional casting. We evaluate the design principles of Al-Cr-Fe-Ni and related systems, noting that SLM-processed Co-free EHEAs frequently achieve yield strengths exceeding 1000 MPa and ultimate tensile strengths (UTSs) surpassing 1300 MPa, while maintaining tensile elongations above 10%-a significant improvement over the coarse-grained structures produced by traditional methods. Furthermore, the study identifies critical processing windows, such as laser energy densities (60-120 J/mm3), required to mitigate micro-cracking and achieve near-full density (>99.5%). By synthesizing recent experimental breakthroughs and AI-driven modeling, this review provides a quantitative roadmap for the precision manufacturing of cost-effective, high-performance EHEAs, bridging the gap between theoretical alloy design and industrial additive manufacturing.

To enhance the mechanical performance of selective laser melting (SLM) fabricated NiTi alloys and broaden their potential for biomedical applications, this study employed pre-alloyed NiTiCu powder (Ni:Ti:Cu = 45:50:5, at.%) to fabricate components via SLM. The effects of processing parameters on relative density, mechanical properties, and microstructural evolution were systematically investigated, and cytotoxicity was further evaluated. The results show that the relative density exhibits a rise-fall trend with increasing laser power, reaching about 99.8% at approximately 120 W. The optimum parameter set for overall mechanical performance was identified as 110 W and 900 mm s(-1), yielding a three-point bending strength of 1979 MPa with a strain of 8.67%, and a tensile strength of 371 MPa with an elongation of 5.2%. X-ray diffraction analysis revealed that the SLM-fabricated NiTiCu alloy is predominantly composed of the B2 austenite phase with a minor NiTi0.8Cu0.2 phase (and partial B19 ' martensite); a moderate energy input was found to refine the microstructure and improve the strength-ductility synergy. Cytotoxicity tests satisfied the "non-cytotoxic" criterion specified in ISO 10993-5. Overall, by optimizing SLM processing parameters, a NiTiCu alloy with high densification, well-balanced strength and toughness, and favorable biocompatibility can be achieved, providing a sound basis for integrated structure-function biomedical applications.

Dye residue‐induced water pollution presents a serious threat to ecological integrity and human health, rendering the development of efficient dye removal materials a critical research focus. In this study, a novel dual‐mesoporous LaNi0.8Fe0.2O3/g‐C3N4 S‐scheme heterojunction photocatalyst was synthesized via a combined sol–gel and templating approach. Its structural, optical, and catalytic properties were systematically characterized to elucidate the structure–activity relationship during dye degradation. Under optimized conditions—employing 15 mg of the P‐L2CN8 catalyst under simulated visible‐light irradiation (λ > 420 nm) for the treatment of 50.0 mL of a 20 mg·L−1 reactive black solution—a high removal efficiency of 94.8% was achieved. Active species trapping experiments confirmed that hydroxyl radicals (·OH) served as the predominant active species in the degradation process. A rational S‐scheme charge transfer mechanism is proposed, which provides both theoretical insight and experimental support for the design of high‐performance photocatalytic materials and the control of dye pollution, underscoring its significant potential for environmental remediation.

Er/Yb-doped silica glasses are promising for three-dimensional displays and optical sensing, but their fixed emission wavelengths limit spectral tunability. Although Al 2 O 3 is conventionally used to modify glass networks and suppress rare-earth-ion clustering, here we demonstrate its ability to tune upconversion (UC) emission. Er/Yb interlayer-doped silica glasses with varying Al 2 O 3 contents were fabricated by selective laser sintering (SLS). The samples exhibited robust green ( 2 H 11/2 , 4 S 3/2 → 4 I 15/2 ) and red ( 4 F 9/2 → 4 I 15/2 ) UC emissions. Increasing the Al 2 O 3 content shifted the green emission maximum from 500 to 550 nm. This tunability is attributed to Al 2 O 3 -induced modifications of the glass network. These results provide a strategy for wavelength-tunable green emission with potential applications in full-color 3D displays and biomedical imaging.

High-purity and high-transparency quartz glass(Hereinafter referred to as quartz glass) is an amorphous material with significant potential in industries such as automotive and aerospace. However, its high brittleness leads to low tensile strength and impact toughness, making it challenging to apply in specialized fields. Auxetic structures are a type of metamaterial with extraordinary mechanical properties, but the corresponding optimization processes have not been fully established. This study proposes the use of topology optimization to achieve controllable auxetic structures, combined with photopolymerization techniques to fabricate high-purity and high-transparency quartz glass samples.The results show that the error of auxetic structures achieved through topology optimization is within 5%, and the fabricated samples exhibit performance close to the international standard ISO 3585, with significantly improved mechanical properties compared to conventional structures.

High-power, high-order Laguerre-Gaussian (LG) beams directly generated within a laser resonator are advance applications in applications related to material processing, optical manipulation, and communication. In this study, we demonstrate a method for intra-cavity generation of high-power, high-order LG modes by introducing a defect spot on the surface of a Yb:YAG thin-disk. Benefiting from the excellent performance of thin-disk lasers under high-power operation, the average output can be scaled to higher power levels. Ultimately, high-power petal-like LG0, fn beams with zero radial order with opposite topological charges n was successfully obtained from the cavity. Specifically, the highest output power of LG0, f8 mode reached 24.6 W, which represents the highest power output for this mode order to the best of our knowledge.

Dye residue‐induced water pollution presents a serious threat to ecological integrity and human health, rendering the development of efficient dye removal materials a critical research focus. In this study, a novel dual‐mesoporous LaNi 0.8 Fe 0.2 O 3 /g‐C 3 N 4 S‐scheme heterojunction photocatalyst was synthesized via a combined sol–gel and templating approach. Its structural, optical, and catalytic properties were systematically characterized to elucidate the structure–activity relationship during dye degradation. Under optimized conditions—employing 15 mg of the P‐L2CN8 catalyst under simulated visible‐light irradiation ( λ > 420 nm) for the treatment of 50.0 mL of a 20 mg·L −1 reactive black solution—a high removal efficiency of 94.8% was achieved. Active species trapping experiments confirmed that hydroxyl radicals (·OH) served as the predominant active species in the degradation process. A rational S‐scheme charge transfer mechanism is proposed, which provides both theoretical insight and experimental support for the design of high‐performance photocatalytic materials and the control of dye pollution, underscoring its significant potential for environmental remediation.

Reliable joining of multi-layer aluminum foil current collectors is crucial for enhancing the performance and safety of high-capacity lithium-ion batteries. However, laser welding of such thin-thick aluminum combinations is often hindered by porosity, cracks and unstable weld-pool behavior. In this study, a ring-mode fiber laser combined with sinusoidal oscillation and linearly gradient power modulation was employed to achieve high-quality lap welding between 80 layers of 1060 aluminum foil (1 mm in total thickness) and a 1.5 mm thick aluminum plate. Welding experiments and thermo-mechanical simulations were conducted to investigate the effects of welding speed (15–45 mm/s) and central-power modulation parameters (−2, 0, +2, +4) on weld morphology, defect formation, and mechanical properties. The results indicate that increasing the welding speed can effectively suppress cracks and improve the shear strength from 249.8 N to 403.9 N, but it also leads to an increase in porosity from 5.78% to 12.26% and deterioration of the weld reinforcement. Higher central-power modulation (+2, +4) transformed the weld-pool geometry from an ω shape to U shape, effectively suppressing fusion-line cracks but leading to increased porosity (up to 8.41%) and deteriorated surface morphology. Overall, a low welding speed of 15 mm/s combined with an optimized power modulation strategy achieves effective crack suppression while maintaining controlled porosity, resulting in a welded joint with superior comprehensive performance. This research provides a robust process solution for high-quality laser welding of multi-layer aluminum foil current collectors in power battery manufacturing.

Weak measurement is an effective approach for detecting small phase shifts. In this work, a method is proposed for determining the three-dimensional orientation of the optical axis in uniaxial crystals, based on frequency-domain weak measurement. The C-axis orientation is decomposed into a transverse azimuthal angle theta (in the plane perpendicular to the optical axis) and a longitudinal cut angle 0 (along the optical axis), and quantitative relationships are established between these angles and the induced phase shifts. By leveraging the weak-value amplification effect, small phase variations are transformed into measurable spectral shifts, enabling decoupled measurements of chi and 0. The angular resolution for chi is 1.9 x 10(-3) degrees, and the phase resolution for 0 is 2.5 x 10(-5) rad. Furthermore, a phase compensation strategy was validated and successfully applied to large cut angle measurements, extending the dynamic range while maintaining high sensitivity. Excellent consistency is observed in repeated measurements of cut angles across four selected sapphire crystals. This approach provides a non-destructive, high-precision solution for crystal processing quality evaluation, offering new possibilities for optimizing polarization-sensitive devices.

NiTi and NiTiCu shape memory alloys (SMAs) with 5 at% Cu were fabricated using Selective Laser Melting (SLM) technology to investigate the impact of Cu addition on tensile properties and phase transformation behaviors. The results show that Cu significantly altered the melt pool temperature and molten metal flow rate during processing. In NiTi alloys, a large number of NiTi2precipitates and dislocations were formed, while NiTiCu alloys exhibited significant B19' phase and twin formations. The distribution of these phases shifted the phase transformation temperatures, increasing the martensite start (Ms) temperature by 15.81 degrees C and decreasing the austenite start (As) temperature by 16.63 degrees C. Consequently, the NiTiCu alloy displayed martensitic behavior at room temperature, enhancing its toughness. The tensile testing revealed a decrease in tensile strength from 879 MPa to 715 MPa, accompanied by a notable increase in strain from 10.88 % to 17.64 %. The results suggest that 5 % Cu optimally balances strength and toughness, making it an ideal addition for improving the mechanical performance of NiTi SMAs.

The analysis of bone marrow cell morphology is essential for the accurate diagnosis of hematological disorders. Traditional manual classification methods are time-consuming and labor-intensive. Although current automatic deep learning techniques mitigate these issues, they may still present significant risks in critical medical diagnostics due to overconfidence in predictions. To tackle these challenges, this paper proposes a novel calibration method called MixCL (Mix-Center Loss). MixCL combines the simple and effective data augmentation method Mixup with deep metric learning Center Loss, achieved through the design of a new loss function. By utilizing Mixup to generate mixing centers that enrich the feature sampling in the feature space, and leveraging the clustering effect of Center Loss to enhance the grouping of similar samples, MixCL combines the strengths of both methods. The effectiveness of MixCL is validated using three real bone marrow cell image datasets, demonstrating significant reductions in Expected Calibration Error (ECE) and Overconfidence Error (OE) for in-distribution samples. For example, in Shifted Windows Transformer model, ECE and OE metrics decreased across all datasets, with reductions averaging 1.72% in ECE and 2.10% in OE. The confidence Kernel Density Estimation (KDE) plot reveals that models using MixCL more effectively manage uncertainty in out-of-distribution samples, ensuring better differentiation between in-distribution and out-of-distribution samples. Thus, the proposed method effectively improves the calibration performance of the model while exhibiting better generalization performance, significantly improved when compared with current advanced bone marrow cell classification methods. Moreover, it has potential applications in various image classification fields, providing reliable confidence estimates.

Fabricating eutectic high-entropy alloys (EHEAs) via selective laser melting (SLM) presents significant potential for advanced structural applications. This study explores the microstructural evolution of Fe32Cr33Ni29Al3Ti3 EHEAs fabricated by SLM under varying laser powers. Electron backscatter diffraction (EBSD) analysis revealed that samples fabricated at 200 W exhibited approximately 70% face-centered-cubic (FCC) and 30% body-centered-cubic (BCC) phases. In comparison, those processed at 160 W showed an increased FCC fraction of 85% with a corresponding reduction in BCC content. Grain size measurements indicated that BCC grains were consistently finer than their FCC counterparts. Thermal simulations demonstrated that higher laser power produced deeper melt pools and broader temperature gradients. By correlating thermal history with phase diagram data, the spatial variation in BCC content was attributed to the differential residence time in the 1350-1100 °C range. This study represents one of the first attempts to quantitatively link local thermal histories with the evolution of dual-phase (FCC + BCC) microstructures in EHEAs during SLM. The findings contribute to the improved understanding and control of phase formation in complex alloy systems, providing valuable guidance for tailoring SLM parameters to optimize the phase composition and microstructure of EHEAs.

Zirconia possesses high strength and good biocompatibility, but the inherent brittleness limits its further application. Inspired by the biomimetic structures, the interpenetrating phases have been demonstrated a toughening effect on brittle ceramic. In practical application, materials are subjected to stresses in different directions, which makes the toughening of materials more complex. This work reports a method of fabricating ceramic/polymer composite by 3D printing, and proposes three gradient structures with varying porosity in Z/XY/XYZ different directions for toughening. Composite infiltrated with hard-tough polymer prevents catastrophic failure and shows an increase of 400

Functional glass surfaces with tunable wettability are of growing interest in optical, biomedical, and architectural applications. In this study, we investigate the influence of femtosecond laser processing parameters—including power, scanning speed, and repetition rate—on the surface morphology, wettability, and optical properties of Panda glass. Laser structuring generated microscale ablation features and increased surface roughness (arithmetic mean height, Sa, rising from ~0.02 µm for pristine glass to ~1.85 µm under optimized conditions). The treated surfaces exhibited enhanced hydrophobicity, with static water contact angles up to ~82° and sliding angles exceeding 50°, indicating significant droplet pinning. Optical characterization further showed a reduction in transmittance at 550 nm from ~92% (pristine) to ~68% after laser treatment, consistent with increased scattering by surface textures. These findings demonstrate that femtosecond laser processing is an effective mask-free method to enhance the hydrophobicity of glass surfaces and establish clear process–structure–property relationships, providing guidance for future optimization toward superhydrophobic performance.

The mechanical performance of NiTi alloys is strongly governed by microstructural features such as densification, grain morphology, and dislocation density. However, quantitative insights into how processing parameters systematically control grain size, high-angle grain boundary (HAGB) fraction, texture characteristics, and kernel average misorientation (KAM) to achieve targeted property tuning remain limited. This study integrates experimental analysis, thermo-fluid coupling simulations, and theoretical modeling to systematically investigate the effects of laser power (100-140 W) and scanning speed (900-1100 mm/s) on the densification behavior and microstructural evolution of NiTi alloys fabricated by selective laser melting (SLM). The simulations reveal the evolution of Marangoni convection within the melt pool under varying energy densities, while metallographic analysis quantifies the correlation between porosity and processing parameters. The optimal process parameters (130 W, 1000 mm/s) yielded a tensile strength of 549 MPa, elongation of 6.39 %, elastic modulus of 21.04 GPa, and microhardness of 316-321 HV. EBSD analysis showed HAGB fractions of 41.7 % (X-Z) and 41.4 % (X-Y), with average grain sizes of 19.03 mu m and 27.44 mu m. TEM revealed abundant linear dislocations and uniformly dispersed NiTi2 precipitates. These results demonstrate that the combination of high densification, strong texture, and multiple strengthening mechanisms enables a favorable balance of strength and ductility, thereby providing both theoretical guidance and practical insights for optimizing SLM-processed NiTi alloys.

In recent years, NiTi shape memory alloys (SMAs) have gained significant attention due to their exceptional functional properties, which are crucial for applications in aerospace, biomedical, and industrial fields. However, traditional manufacturing techniques often fail to optimize the mechanical properties of NiTi alloys, primarily due to limitations in laser absorption and microstructural control. This study explores the potential of blue laser (lambda = 455 nm) additive manufacturing for the fabrication of high-performance NiTi alloys. Using a thermo-fluid coupled finite element model, we examined the impact of processing parameters on the temperature and velocity fields within the melt pool. Experimental results demonstrated that the blue laser significantly improved the alloy's microstructure, leading to the formation of a (100) texture, abundant Ni3Ti4 precipitates along high-angle grain boundaries, and a high density of geometrically necessary dislocations within the grains. These micro-structural enhancements contributed to exceptional mechanical properties, including a tensile strength of 631 MPa, yield strength of 150 MPa, average microhardness of 255 HV, and a friction coefficient of 0.4208. This research presents a novel approach for the high-performance fabrication of NiTi alloys, emphasizing the advantages of blue laser technology for improved microstructural regulation and mechanical optimization in additive manufacturing.

Sapphire-steel interfacial bonding determines the reliability and safety of aerospace, marine, medical devices, and nuclear systems. However, conventional laser transmission welding induces microcracks in sapphire, compromising joint integrity. In this work, a controlled unilateral melting (UM) strategy using a nanosecond fiber laser was proposed to suppress microcrack formation. By controlling the welding temperature (1672-2323 K) at the interface, only stainless steel 304 (SS304) was selectively melted while maintaining sapphire in a solid state. A simulation model based on Finite Element Method (FEM) was established to describe the welding process. This method effectively minimized interfacial thermal stress and preserved the single-crystal integrity of sapphire. Compared to conventional bilateral melting (BM), UM welding increased the cracking load by 703 % and enhanced shear strength by 70 %. Elemental and microstructural analyses confirmed the formation of a stable (Cr, Al)2O3 transition layer in UM weld. Failure mechanisms changed from brittle fracture within sapphire to ductile failure in SS304, ensuring superior mechanical performance. The proposed UM method demonstrates significant potential for high-reliability sapphire-metal welding in industries and provides a novel inspiration for laser welding mechanisms.

The excellent properties of high-entropy alloys (HEAs) and the high cooling rate characteristics of the selective laser melting (SLM) technique make them possess great application prospects. In order to make full use of the reported experimental data of SLM manufactured (SLM-ed) HEAs and to enhance the development efficiency of SLM-ed HEAs, this study carries out the phase prediction work of SLM-ed HEAs by machine learning techniques. We collected 172 SLM-ed HEAs samples (including 88 face-centered cubic (FCC) alloys, 31 body-centered cubic (BCC) alloys, and 53 dual-phase (FCC+BCC) alloys) and developed a machine learning (ML) HEAs phase structure prediction framework using volumetric energy density (VED), a process parameter of SLM, as one of the features, and ultimately achieved a prediction accuracy of 85%, established the linkage between the variation of VED and the phase structure of the SLM-ed HEAs. The reliability of the model was verified by experimentally preparing several AlxCryCuzFeuNiw system HEAs. Larger atom volume (VA) and elemental density values differences (delta(D)) were found to favour the formation of the SLM-ed HEAs BCC phase by interpretable analysis, while smaller VA and delta(D) favoured the formation of the FCC phase. In addition to this, the sensitivity matrix and three-dimensional cubic section plots reveal that Al has a great influence on the phase formation of the AlxCryCuzFeuNiw system of HEAs, with most of the alloys forming the FCC phase when the Al content is less than 10% (at%), and the majority of the alloys forming the BCC phase when the Al content is greater than 20%.

Fiber laser is a stable light source for improving the stability of laser-induced breakdown spectroscopy (LIBS) under long-time operation. However, LIBS based on fiber laser ablation (FL-LIBS) also suffers from the self-absorption effect. In this paper, the self-absorption effect in FL-LIBS was experimentally investigated. The influence of the fiber laser ablation process on self-absorption was studied. The law of ablation on the surface of micro-alloy steel samples based on high pulse repetition rate (PRR) fiber laser ablation was qualitatively analyzed. The spectral data were explored based on the discrete wavelet transform and the spectral internal standard method. The result was an R2 of the calibration curve increasing from 0.955 to 0.995. The influence of the laser output power and defocus amount (DA) on the self-absorption effect was investigated. Through the adjusted selection of laser output power and single pulse ablation area (SPAA), compared with the situation when the laser was in focus, the system self-absorption factor can be reduced from 1.29 to 0.61, and the performance index of the calibration curve such as root mean squared error of cross validation (RMSECV) and relative standard variation (RSD) had been improved from 0.18 to 0.13 wt%, 6.61 to 5.88%, respectively. Finally, it was concluded that self-absorption would increase with the increase of laser output power and SPAA in high PRR FL-LIBS system, contrary to conventional LIBS based on low PRR laser ablation. This work investigated the mechanism and suppression of the self-absorption effect in FL-LIBS, aiming to promote the industrial application in the future.

Selective laser melting (SLM) of high entropy alloys (HEAs) shows great potential in industry applications and annealing was always used as a post-processing method after SLM. A dual-phase (DP) Co-free HEA was manufactured by SLM and annealed at 900 degrees C in this work. The annealed HEA exhibited super high yield and tensile strengths ( 1224 and 1363 MPa, respectively), higher than those of the as-printed sample, primarily attributed to grain refinement and spinodal decomposition with FCC phase (rich in Ni/Al/Ti) and BCC phase (rich in Cr/Fe) decomposing into FCC (rich in Fe), B2 (rich in Cr, poor in Ni), and L12 (rich in Ni/Al/Ti, poor in Fe/Cr) during annealing. The annealed DP Co-free HEA exhibits notably superior strength to other Co-free HEAs or medium entropy alloys (MEAs) produced via SLM. Due to their affordability, Co-free HEAs show immense potential for widespread commercial use, and this study explores annealing in SLM to improve the mechanical properties of HEAs. The high-strength annealed DP Co-free HEA could be especially valuable for structural elements in construction applications.