For conducting a torsion test on a microfiber, measuring the micro-moment is essential. A novel compliant rotational reduction mechanism (CRRM) has been designed to enhance the actual rotation resolution of rotational micro-actuators, which can be used for the torsion test of a microfiber; however, existing research focuses on the rotation gain modeling, rather than the measurement of output micro-moments. This paper presents a noncontact measurement method designed to determine the output micro-moment of the novel CRRM, utilizing its output torsional stiffness. The noncontact measurement framework for output micro-moment is first outlined. Based on Castigliano’s second theorem, small-deflection-based model for the output torsional stiffness of the CRRM is established. Furthermore, geometrically nonlinear model is developed using the beam constraint model. Subsequently, the validity of the proposed static model for the CRRM is verified through FEA and experiments. Finally, non-contact measurement of micro-moment is achieved in conjunction with a microscopic visual measurement system.

Optical inspection of highly reflective cylindrical components—such as stainless-steel vessels featuring both planar and curvilinear surfaces—presents significant challenges due to complex geometric distortions in single-pass imaging. This study proposes a line-scan imaging framework that integrates synchronized kinematic control with geometry-aware distortion correction. The system addresses shape deformations through three coordinated modules: (1) parametric synchronization between rotational motion and image acquisition ensures full-surface coverage; (2) scanline-specific 1D projective transformations correct perspective distortions on toroidal sidewalls; and (3) adaptive polar coordinate remapping restores radial symmetry on circular bases. Experimental results demonstrate subpixel-level geometric correction accuracy, validating the proposed framework’s effectiveness in eliminating geometric aberrations with low computational complexity and without reliance on data-driven training, while maintaining compatibility with defect detection and quantitative surface analysis of specular cylindrical specimens.

Hot-forming processes including die casting, hot stamping, and injection molding impose high demands on die steels, where the choice of steels directly impacts the service life of molds, speed of production, costs and product quality. Currently, most research focuses on properties such as strength, toughness, wear resistance, and oxidation resistance of die steels, while neglecting the critical property of thermal conductivity. This review emphasizes the importance of high thermal conductivity for die steels and, for the first time, conducts a comprehensive review centered on the thermal conductivity of steel, thereby addressing the long-standing gap in systematic summaries in this field. This review comprehensively summarizes the mechanism of thermal conduction and key microstructural factors influencing thermal conductivity. Based on this, two main approaches for enhancing the thermal conductivity of steels are discussed, including alloy composition optimization (low alloying element content, particularly with low silicon and chromium levels) and heat treatment process optimization (heat treatment like quenching and tempering is superior to quenching and deep cryogenic treatment, and appropriately increasing the tempering temperature within a certain range). High-thermal conductivity steels often face challenges such as insufficient mechanical properties and poor oxidation resistance. Since conventional strengthening methods are of limited feasibility, this review provides a fresh perspective by highlighting an emerging approach—reinforcing die steels with trace nano-ceramic particles to overcome the traditional trade-off between thermal conductivity and mechanical/oxidation properties. This integrated angle and the proposed strategy constitute a notably novel contribution for a review paper in this field.

Duplex stainless steel (DSS) has emerged as a preferred material for critical components in the nuclear power, petrochemical, and offshore engineering. However, laser welding of DSS is always compromised by coarse columnar ferrite grains and severe phase imbalance, which degrade the mechanical integrity and corrosion resistance of the joint. This study proposes an in-situ inoculation strategy utilizing a porous, columnar TiN coating deposited via oblique angle deposition (OAD) in a reactive magnetron sputtering system as a pretreatment prior to laser welding. During the welding process, thermal shock induces the fragmentation of the TiN coating into sub-micron particles. Driven by melt pool hydrodynamics, these particles disperse to serve as potent heterogeneous nucleation sites, effectively promoting grain refinement during solidification. The effects of laser power (900-1800 W) and TiN inoculation on the microstructural evolution and mechanical performance was systematically evaluated. The results demonstrate that the dispersed TiN particles trigger a complete columnar-to-equiaxed transition within the ferrite matrix. At an optimal power of 1800 W, the inoculation strategy refined the average ferrite grain size from 136.4 mu m to 31.5 mu m and increased the austenite fraction from 19.4% to 39.8%, with the austenite morphology evolving from dispersed intragranular precipitates to a comprehensive networked structure. The microstructural optimization yielded enhancement in ultimate tensile strength (772 to 836 MPa), yield strength (607 to 661 MPa), and elongation (14.3% to 22.7%), and improved corrosion resistance. This work elucidates the mechanism driving particle-induced grain refinement and phase rebalancing under high energy input, establishing a viable pathway for fabricating reliable high-performance DSS joints via sub-micron inoculation, which is promising in real applications.

Vat photopolymerization (VPP) has attracted extensive attention in fabricating complex ceramic components, but critical contradiction still exists between manufacturing (printing and debinding) efficiency and structural performance (mechanical properties and surface quality). This study novelly integrates high-speed continuous 3D printing with rapid debinding to fabricate high-quality ceramic parts by introducing low-viscosity, volatile, non-reactive diluent (gamma-valerolactone, GVL) into the SiO2 slurry. The introduction of the diluent resulted in a reduced adhesive force by over 80% between cured part and constrained window when the amount of the GVL was over 50 wt%, contributing to continuous 3D printing of layer-less ceramic parts. The reduction of adhesive force can be mainly attributed to the lubrication effect and the decrease of elastic modulus. Moreover, the debinding rate can be accelerated remarkably to 200 degrees C/min, more than one order of magnitude faster, to obtain defect-free ceramic parts with improved strength by 30%-90%. This can be explained by the formation of sub-micro pores and micro channels following GVL evaporation to alleviate expansion stress during both debinding and sintering. In addition, the sintered SiO2 components by continuous 3D printing demonstrated reduced longitudinal and transverse shrinkage ratio from 1.36 to 1.02 and lowered surface roughness Ra from 39.1 mu m to 4.8 mu m, compared to conventional layer-by-layer printing. This method offers valuable insight into vat photo-polymerization of ceramics and provides new guidance for high-speed 3D printing and rapid debinding for ceramics with improved mechanical properties and surface quality.

To address the challenge of disordered crysto-oriented pore (COP) formation during organized porous InP growth, we demonstrate a strategy based on laser interference lithography-defined electrochemical etching to achieve intact porous InP structures. Simulation studies reveal that the electric field increases monotonically as the pore-opening diameters decrease (from 1 μm to 0.4 μm at a constant period of 2 µm) and as the period lengths decrease (from 5 μm to 0.2 μm with a 1 : 1 duty ratio), under a constant current density of 320 mA cm-2. Experiments confirm that the COP layer thickness decreases with reduced pore-opening diameters and periods at the same current density, ultimately vanishing at a period of approximately 0.4 μm (1 : 1 duty ratio). These results indicates that COP layers can be eliminated while the pore-opening dimensions approach certain critical values, providing a new approach for fabricating defect-free porous InP structures via laser interference lithography-defined electrochemical etching.

The bonding strength between Micro-LED chips and the driving substrate directly affects the performance and operational stability of the display panel. To address the current challenges in chip interconnection quality measurement—namely the stiffness mismatch of the measurement probe and its insufficient low-load capacity, which prevent accurate measurement of the bonding force between Micro-LED chips and the substrate—we propose a method based on a high-sensitivity "force--deformation" cantilever amplification mechanism to measure the bonding force of a single Micro-LED chip. The amplification mechanism is analyzed, and a prototype cantilever is developed. Precise calibration and durability tests are performed on the cantilever deformation and the chip bonding force, respectively. Finally, a bonding force measurement experiment is completed on a Micro-LED chip sample. The results show that the sensing amplification ratio of the micro-force measurement cantilever reaches 158.52 times. Under a sustained maximum bonding force loading of 0.028 N, the elastic coefficient fluctuation of the cantilever within 124 hours is only 3%, demonstrating high-precision measurement capability. This micro-force cantilever thus meets the stringent requirements for measuring the bonding force of Micro-LED chips, providing effective support for the evaluation of Micro-LED chip bonding strength.

High-temperature alloys have become an indispensable material in aerospace, automotive, and energy industries due to their outstanding high-temperature strength and creep resistance. However, the growing requirements for the superalloys underscores the necessity of enhancing their performance. In recent years, nano strengthening technology has been introduced into high-temperature alloys to further improve their performance. The incorporation of nanoparticles can not only refine grains and uniform microstructure, but also improve the strength, hardness, corrosion resistance, tensile properties, and creep behavior. In order to realize the wider application of nanoparticle-reinforced superalloys in the future, this review systematically summarizes the influence of nano-strengthening technology on the microstructure and high-temperature creep resistance of superalloys. It addresses the limitations of traditional methods and deeply discusses the specific mechanisms of nano-strengthening through process routes and strengthening methods. This review aims to promote the innovative development of superalloys and provide theoretical support for the research of next-generation high-performance high-temperature alloys.

Against the backdrop of rapid advancements in lightweighting and integrated die-casting technologies for new energy vehicles, aluminum alloys have emerged as the core lightweight material for automotive structural components due to their excellent specific strength, corrosion resistance, and formability. However, traditional die-cast aluminum alloys generally rely on heat treatment processes to achieve strength and toughness. This not only significantly increases process costs and production lead times, but also leads to critical defects such as blistering and dimensional distortion in large integrated die-castings during heat treatment. Consequently, the development of high-strength and high-toughness die-cast aluminum alloys that meet service requirements in their as-cast state has become an urgent industry need. Although significant progress has been made in recent years in the research on microstructural control and performance enhancement of die-cast aluminum alloys for automotive applications, a systematic, integrated analysis of the strengthening mechanisms for the two mainstream alloy systems—Al-Si-Mg and Al-Mg-Si—remains lacking. This paper systematically reviews the microstructural evolution patterns and intrinsic mechanisms of performance enhancement for these two alloy systems, providing important theoretical references for the composition design and microstructural control of next-generation high-strength, high-toughness aluminum alloys without subsequent heat treatment, as well as supporting the further development of lightweighting technologies for new energy vehicles.

Magnesium alloys hold considerable promise for lightweight structural applications due to their low density and high specific strength. However, their intrinsic hexagonal close-packed crystal structure results in a limited number of active slip systems, inadequate high-temperature strength, poor creep resistance, and pronounced flammability. These inherent drawbacks significantly restrict their utilization in demanding high-temperature and severe service environments, such as those encountered in aerospace and transportation sectors. To overcome these performance limitations, alloying with rare earth elements has proven to be an effective strategy. This article provides a detailed analysis of the regulatory effects and underlying mechanisms by which rare earth elements influence the microstructure of magnesium alloys. It further examines the critical roles and mechanisms by which RE additions significantly enhance properties such as creep resistance, superplasticity, fatigue life, and flame retardancy. The discussion also extends to the synergistic effects achieved by composite alloying with elements such as Al, Zn, and Ag, or by the incorporation of nanoparticle/metallic particles, which collectively contribute to multiple strengthening mechanisms. Future research should focus on the design of Mg alloys with low or even zero heavy rare earth content, the in-depth elucidation of multiscale structure-property relationships, the integration of advanced processing technologies, and the development of lifetime prediction models under extreme environments. These efforts will be essential for promoting the reliable application of magnesium alloys in a wider range of high-temperature structural scenarios.

Brittle bio-ceramics materials intrinsically lack a favorable trade-off between strength and toughness, limiting their ability to achieve bone-matched mechanical properties and clinical applications. Inspired by the hierarchical architecture and composition of natural bone, ceramic-polymer interpenetrating phase composites (IPCs) were designed and fabricated by combining 3D-printed porous (3-TCP ceramics with subsequent PCL infiltration. Three representative triply periodic minimal surface (TPMS) architectures with varied wall thicknesses were employed to regulate the volume fraction and spatial distribution of ceramic and polymer phases inside the IPCs. Using by microstructural characterization, quasi-static compression testing, and dynamic cyclic loadingunloading, the influences of geometric topology and structural parameters on the strength-toughness response were thoroughly investigated. The response relationship and mechanism between structure and mechanical properties were further analyzed. The results showed that polymer fully infiltrated the continuous channels within the porous ceramics and formed strong mechanical interlocking at both the phase interface and ceramic internal micropores. The strength and strain energy density of the (3-TCP/PCL IPCs were improved by 5-11 and 7-30 times respectively, and their mechanical response was dependent on the biphasic volume fraction and interfacial bonding. Compared with brittle fracture of porous ceramics, the IPCs transformed into ductile energydissipative deformation. Under dynamic cyclic compression, the composites possessed excellent deformation recovery and high energy-dissipation capability. The study will provide important foundation for the development of high-performance personalized biomedical implants by linking IPCs' architecture to their mechanical functionality.

Driven by the proposed new circular economy goals and “dual carbon” strategy (carbon peak and carbon neutrality), the inherent recyclability of aluminum and its alloys makes their secondary utilization critical for green and sustainable development. Owing to its controllable source, scrap aluminum produced by manufacturing industries, such as the automobile, aerospace, and electronics industries, represents a high-value resource that will be critical for the global supply of aluminum and its alloys. However, large amounts of impurity elements (Fe, Si, Mg, Cu, and others) are introduced into scrap aluminum during the recycling process, among which Fe is the most harmful. Consequently, recycled aluminum is largely restricted to lower-grade applications, precluding its comprehensive substitution of primary aluminum. This article reviews the detrimental effects of Fe and the resulting Fe-rich phases (FRPs) on aluminum alloys, summarizes existing Fe removal and deterioration mitigation methods, and evaluates the industrial feasibility of these methods to provide comprehensive theoretical guidance for future FRP control technology. Moreover, this review provides guidance for resolving the impediments to the grade preservation and subsequent use of industrial recycled aluminum.

Magnesium alloys exhibit poor room-temperature formability due to their hexagonal close-packed (HCP) structure, which limits their widespread application. Superplastic forming offers an effective solution, enabling elongations typically from ∼400% to over 1000%, and exceeding 3000% under optimized severe plastic deformation (SPD) conditions. This review provides a critical and systematic assessment of the microstructural design principles governing superplasticity, emphasizing the roles of fine equiaxed grains (<10 μm), thermal stability, and texture weakening, as well as the processing routes required to achieve them. Grain boundary sliding (GBS) is confirmed as the dominant deformation mechanism, while its stability relies on accommodation mechanisms including dislocation creep, diffusion creep, and dynamic recrystallization. The capabilities and limitations of advanced processing techniques, such as equal channel angular pressing (ECAP), high-pressure torsion (HPT), and friction stir processing (FSP), are comparatively evaluated in terms of grain refinement efficiency and industrial applicability. Particular attention is given to particulate reinforcement strategies, where fine and well-dispersed particles enhance superplasticity through grain refinement and boundary stabilization, whereas coarse or agglomerated particles promote cavitation and premature failure. Future developments are expected to benefit from machine learning-assisted optimization of composition, processing, and microstructure–property relationships, enabling accelerated design and improved predictability of high-performance superplastic magnesium alloys.

To face the global challenge of heat dissipation in high-performance chips, we developed a low-cost heat sink due to the high-efficiency radiation in infrared wavelength based on microstripes and nanograss-shaped copper oxides on the copper surface, which was fabricated by laser direct writing and chemical blackening. The results show that the surface area of the black copper heat sink (BCHS) was 1.47 times larger than that of the raw copper substrate due to the formation of microstripes and nanograss-shaped copper oxides, and an emissivity exceeding 98% across the 2.5-15 mu m wavelength range was achieved through a process involving laser direct writing with the 20 mu m interval and subsequent chemical blackening for 50 s. Furthermore, the as-fabricated black copper heat sink displays superior heat dissipation performance. Under a constant heating power of approximately 3 W for the simulated CPU, the temperature decreased by approximately 11.7% from 110.0 degrees C to 97.1 degrees C. In summary, this work proposes a practical strategy to improve the performance of heat sink by enhancing infrared radiation. This approach is suitable for mass production and commercialization based on combining ordinary laser direct writing with chemical blackening technology.

Dissimilar joints are widely used in various contexts, including electric vehicles, aerospace, and structural applications. Compared to conventional fusion welding and brazing techniques, ultrasonic welding of dissimilar joints exhibits distinctive microstructural and property characteristics. This paper reviews the outcomes of ultrasonic welded dissimilar joints and provides a comprehensive overview of the scientific principles underlying these processes. This work begins with an introduction to the formation of intermetallic compounds and their effect on the properties of ultrasonic welded dissimilar joints. A discussion of the correlation between ultrasonic welding parameters and the microstructure of the welded interface is then presented, taking into account interfacial energy input and microstructural evolution. Furthermore, the effect of additional energy on the improvement of joint performance has been considered. It is evident that an increase in energy input, achieved through parameter optimization and the application of auxiliary energy, can facilitate a modification of the joint behavior and enhance the mechanical integrity of the weld. Moreover, the article examines recent advances in optimizing the interfacial intermetallic composition through intermediate sandwich metals, enhancing joint performance. Future research directions and opportunities for improving the performance of ultrasonic welded dissimilar joints are also presented.

Hot work die steels are extensively applied in hot forming, where dies are subjected to high temperature and mechanical stresses and are prone to fatigue failure. A novel approach was proposed to synergistically manipulate hot work die steels by increasing Cr content and introducing TiC nanoparticles, showing far superior oxidation resistance and hot-cold alternating fatigue resistance compared to the international high-end DIEVAR die steels. On the one hand, the introduction of ceramic nanoparticles contributed to the enhanced oxidation resistance of the steels by promoting the formation of a thicker and denser Cr2O3 oxide film on the steels surface. On the other hand, the high-temperature microstructure stability and tempering resistance of steels were also improved through microstructure refinement and matrix strengthening. This effectively inhibited the initiation and propagation of hot-cold fatigue cracks, thereby significantly improving the resistance of steels to hot-cold alternating fatigue. This work provides a theoretical basis for understanding the modification of the high-performance hot work die steels.

Vat photopolymerization (VPP) is widely studied for manufacturing ceramic parts due to its cost-effectiveness, high efficiency, and excellent resolution. However, defects in complex, thick-walled structures induced by manufacturing process often restrict its application. This study reports the successful development of defect-free, thick-walled ceramic parts using VPP by incorporating gamma-valerolactone (GVL), a circular, safe, biomass-derived diluent, into SiO2 suspension. This addition effectively controlled defect formation throughout both printing and debinding. Specifically, introducing 50vol% GVL into organic solution reduced the viscosity of the SiO2 suspension by 38-48% at a high solid loading of 67vol%, thereby eliminating inner pore defects during printing. Furthermore, this modification reduced the volume shrinkage of the SiO2 suspension during printing by 40%, significantly alleviating residual shrinkage stress. Remarkably, the toughness of the green sample containing 50vol% GVL remained exceptionally high during printing and debinding, effectively resisting stress-induced defect formation, particularly interlayer cracks. Microstructural analysis revealed that sufficient exhaust ducts formed when the diluent evaporated at the first debinding stage under lower temperatures, facilitating the release of pyrolyzed gases at the second debinding stage under higher temperatures and thus mitigating gas expansion stress. The defect-free mechanisms can mainly be the balance of the mechanical properties and the process-induced stresses. These findings indicate that ceramic suspensions enhanced with high concentration of non-reactive diluent hold significant promise for manufacturing defect-free, thick-walled ceramic parts through VPP in industrial applications.

In this work, the synergistic effects of the modifier Al-3P master alloy and nano-TiB2 ceramic particles on the microstructure and mechanical performance of cast eutectic Al-Si alloys were investigated. Results showed that AlP and nano-TiB2 particles served as efficient heterogeneous nucleation sites of Si and alpha-Al, respectively. Incorporated TiB2 and Al-3P performed the best manipulating potency on the solidification microstructure of Al-Si alloys than separately added, primary Si was significantly refined and the transition of Al-Si eutectic was promoted. Room-temperature and high-temperature tensile strength were also markedly enhanced, the yield strength, ultimate tensile strength and fracture strain of eutectic Al-Si alloys manipulated by Al-3P + nano-TiB2 particles were increased by 36.4%, 31.7% and 32.1% at 250 degrees C and 60.0%, 42.0% and 50.9% at 300 degrees C, respectively, in comparison to the unmodified alloys. The enhanced high-temperature strength was attributed to the refinement of primary Si and alpha-Al, which was achieved through the synergistic effects of nano-TiB2 particles and Al-3P. Then the grain boundary density increased, with finer eutectic Si and nanoparticles being effectively pinned at the grain boundaries, thereby boosting the mechanical performance. This study provides theoretical research and experimental basis for the development and application of heat-resistant aluminum alloys.

To face the challenge of the fast, large area, and high-precision manufacturing for flexible structural color films, a strategy based on soft lithography to fabricate polydimethylsiloxane (PDMS) structural color films was proposed in this paper. The large area periodic structures as the template were obtained by means of laser interference lithography. After soft lithography, SEM images showed that the morphology and period are completely inversed with the templates. The colors of the films have an obvious angle dependence which was proved by an angle-resolved spectrometer(ARM), in which the peak position of the reflectance spectrum changed similar to 267 nm as the angle increasing from 10. to 25. for the period similar to 2.126 mu m. In addition, the peaks of reflectance spectra have also an obvious redshift of similar to 162 nm with increasing elongation ratio up to 40 %. Furthermore, the reflection peak of the flexible film will stably change between similar to 697 nm and similar to 617 nm before and after stretching from 0 to 40 % for 11 times. In conclusion, we explore an efficient way with the fast, large area, and high precision to fabricate flexible structural color films in the atmospheric environment, showing the potential application in optical anti-counterfeiting and mechanical sensor.

In this study, TiC + TiB2 nano-ceramics reinforced high-Cr die steels were successfully prepared using aluminum-based master alloy as a carrier for the nano-ceramics. The impact of nano-ceramics on the microstructure of steels as well as the tensile properties and friction and wear properties under high temperature conditions were explored. The incorporated nano-ceramics can significantly refine the microstructure of steels, resulting in finer and more uniformly precipitated carbides, thereby effectively improving the mechanical properties of steels. Compared with unmanipulated high-Cr die steels, the high-temperature (550 degrees C) yield strength of high-Cr steels reinforced with 0.02 wt% nano-ceramic was increased from 963 MPa to 1274 MPa. The volume wear rate of nano-ceramics reinforced high Cr steels reached 11.9 x 10-13 m3/m, 3.4 x 10-13 m3/m, 5.6 x 10-13 m3/m and 6.3 x 10-13 m3/m under the four conditions of 400 degrees C-30 N-300 r/min, 550 degrees C-20 N-300 r/ min, 550 degrees C-30 N-300 r/min and 550 degrees C-40 N-300 r/min, which were reduced by 23.7 %, 34.6 %, 34.9 % and 35.1 % respectively. These results provide a new insight into improving the high-temperature friction and wear properties of steels.