The United States General Electric Company (referred to as GE) has conducted research on SiC_f/SiC composite materials since the 1980s. The successful application and commercialization of GE’s SiC_f/SiC composites in engine systems were achieved after 30 years of continuous investment (nearly 1.5 billion USD) and the collaborative efforts of hundreds of scientists and engineers. This paper details the spiral development history of GE’s prepreg-melt infiltration (MI) SiC_f/SiC composites, focusing on their innovative applications in hot-section components for gas turbines and aero-engines. Through case studies of several critical hot-section components, GE’s research paradigm of “demand traction, technology verification, and engineering iteration”is elucidated. Furthermore, the 10-year progressive design iteration path of the 7FA engine turbine shroud is systematically analyzed, revealing the synergistic optimization logic between service failure feedback and forward design validation. In light of international advancements, this paper interprets GE’s establishment of a“material-process-test”technological barrier through vertical supply chain integration, digital twin-driven process optimization, and machine-learning-based inspection systems. GE’s experience demonstrates that technological breakthroughs require a balance between long-term fundamental research and agile engineering iteration. For domestic development, a closed-loop“design-manufacturing-assessment”research and development process should be established, guided by critical components, alongside multidisciplinary collaboration mechanisms. Additionally, China should strengthen foundational capabilities by leveraging universities and national research and development centers for mechanistic studies, implement multi-dimensional optimization under thermo-mechanical-chemical coupling constraints, accelerate industrial ecosystem construction, integrate fragmented resources, and build rapid“industry-academia-research”verification platforms. A digital transformation strategy encompassing full-chain data acquisition and AI integration is also essential. Finally, by synthesizing successful international practices and adapting them to China’s context, an autonomous development roadmap covering“basic research, pilot verification, standard formulation, and industrial synergy”is proposed, providing methodological guidance for advancing ceramic matrix composite technologies in high-thrust-to-weight-ratio aero-engine applications.

Light-curing 3D printing technology stands out as one of the oldest, fastest-growing and most widely used technologies in the field of 3D printing. This technology utilizes ultraviolet or other light sources to rapidly solidify liquid photosensitive polymers, creating products with complex geometrical structures that are difficult to achieve with traditional manufacturing methods. This paper summarizes the latest research progress in photocurable polymer materials for 3D printing, covering various types of photocurable polymers including thermoplastics with high remoldability, thermosets with good structural stability, and hydrogels with hygroscopic network cross-linking structures. Additionally, the applications of photocurable 3D printing polymers in various fields such as biomedical, flexible electronic devices, soft robotics, energy storage, and aerospace are discussed in detail. This review also explores the application of photocuring technology in 4D printing, highlighting the potential of 4D printing in dynamic materials and smart manufacturing. In the future, light-curing 3D printing technology is expected to advance toward the development of high-performance polymer composites, the integration of intelligent and automated printing systems, and the deep integration with cutting-edge technologies such as artificial intelligence, continually driving its applications and innovations in high-tech fields and advanced manufacturing.

Equiatomic Ni-Ti alloys have been widely applied in biomedical and industrial fields, because of their shape memory effect and superelasticity originating from thermos-elastic martensitic transformation. The theoretical and experimental studies in recent years indicated that when doping sufficient amounts of defects (excess solute atoms, foreign alloying dopants, dislocations and nanosized precipitates) into equiatomic Ni-Ti alloys, the resistance from such defects could suppress the first-order martensitic transformation and achieve strain glass transition with the formation of randomly short-range ordered nanodomains. The strain glass transition is characterized by some typical features such as invariant macroscopic structure, broken ergodicity, frequency dependence of dynamic mechanical properties and high damping capacity. In spite of no first order martensitic transformation occurred during cooling, strain glass can exhibit unique shape memory effect and superelasticity because of the stress loading induced transformation from strain glass to martensite and the reversed transformation by stress unloading. The superelasticity of strain glass alloys are closely related to the type and concentration of defects. The strain glasses with moderate concentration of defects exhibit the superelastic behavior similar to conventional Ni-Ti based alloys. By contrast, under temperature or/and stress fields the strain glass ↔ R transition could occur in the strain glasses with high concentration of defects, leading to the superelasticity with small recovery strain and slim hysteresis over a broad temperature range. Strain glass transition could be achieved in Ni-Ti alloys by deformation to introduce large number of dislocations. If only the evolution of nanodomains is involved and no B19′ martensite forms in the Ni-Ti strain glass under external stress, the alloy could perform large linear superelasticity with slim hysteresis. The underlying mechanism for such superelastic behavior lies in that under stress the evolution of nanodomains does not need nucleation, and the energy loss for nucleation can be avoided. In the present paper, the proposition, novel properties and the research progress of the strain glass transition in Ni-Ti based alloys were reviewed. The principle for designing Ni-Ti based alloys with superelasticity in wide temperature range and their applications in engineering are briefly introduced.

Diamond-reinforced metal matrix composites, which exhibit unique properties of both metals and diamonds, are used as functional and wear-resistant materials in various fields. Additive manufacturing technology provides a novel approach for fabricating complex components of metal/diamond composites, significantly enhancing the design versatility of components. Based on several key additive manufacturing techniques, including selective laser melting, laser cladding and cold spraying, this paper introduces the research progress in the additive manufacturing of metal/diamond composites. It covers powder raw materials, core processing technologies and practical applications. Emphasis is placed on discussing the causes, consequenses and potential solutions for sputtering and diamond graphitization that may occur during the manufacturing process. Finally, the main challenges and future development directions of metal/diamond composites in additive manufacturing are summarized. The main manifestations are as follows: in the additive manufacturing process, problems such as diamond splashing, interface control between metal and diamond particles, graphitization of diamond and damage to diamond particles occur. The key issues to be addressed focus on optimizing the forming process to achieve coordinated control of the composite material’s density, interface bonding and diamond protection.

Thermoplastic composites（TPCs）have exhibited immense potential in aerospace applications, attributed to their exceptional toughness, weldability, recyclability, and efficient processing cycles. However, the manufacturing of complex structures is hindered by the high melting points and viscosities of their constituent resins. Resistance welding, leveraging Joule heating to induce interfacial melting and bonding, emerges as a viable alternative to mechanical fastening and adhesive bonding. This review delves into the fundamental principles underlying resistance welding, strategies for optimizing key process parameters, recent advancements in heating elements, and large-scale welding techniques, such as sequential and continuous resistance welding. The findings indicate that optimizing process parameters and improving heating elements can significantly enhance joint strength. To achieve engineering application of resistance welding technology, further research should be focused on process stability, reliability of welded joints, large-scale welding, and other issues.

High-performance thermoplastic resin-based composites have shown broad application prospects in the aviation manufacturing technology due to their excellent mechanical properties, environmental resistance, chemical resistance, recyclability, and rapid molding. In recent years, with the accelerated commercialization of high-performance thermoplastic resins such as polyphenylene sulfide（PPS）, polyetherimide（PEI）, and polyaryletherketone（PAEK）, the related prepregs and molding technologies have been continuously optimized, promoting the industrial application of such materials. This paper systematically reviews the current development status of high-performance thermoplastic resin-based composites, focusing on their material systems and commercialization progress, prepreg preparation, advanced manufacturing technology and application. It proposes key development directions for high-performance thermoplastic resin matrix composites, in order to provide reference for personnel in engineering and technical fields such as aerospace, and promote the innovative development and application of high-performance thermoplastic resin matrix composites.

The machine learning technology has broad prospects in the field of aerospace materials and plays an important role in material selection, design, and optimization. Firstly, a brief discussion was made on the advantages and potential of machine learning technology in the aerospace field, outlining the technological developments, algorithm categories, features, and limitations. The conventional or potential applications of machine learning in scientific exploration, especially in complex material data formats, are introduced. Secondly, the research status of machine learning in aviation materials is mainly focused on, discussing the recent progress in utilizing machine learning to assist in the research of high-temperature alloy materials, high-strength structural materials, thermal protection coating materials, as well as functional and smart materials. The strategies and methods of machine learning-driven aviation material research are elucidated. Finally, the challenges encountered in machine learning-assisted aerospace material research and development are examined. Facilitating the transformation of aerospace material research towards the fourth paradigm of data-driven materials science necessitates efforts in promoting the open sharing of data resources, integrating domain knowledge and physical laws more deeply into machine learning models, and ensuring feature consistency across different data types.

Carbon fiber reinforced thermoplastic composite（CFRTP） is increasingly utilized in aerospace and automotive manufacturing sectors owing to its exceptional specific strength, strong toughness, and weldability. Induction welding stands as a pivotal method for fabricating typical CFRTP components. However, the intricate interplay of magnetic, thermal, and stress coupling during the induction welding process, along with its evolution and distribution characteristics, remains unclear, significantly impeding the cost-effective, efficient, and high-quality production of CFRTP components. In this study, a magnetic-thermal-mechanical coupling simulation model is developed for the induction welding of CFRTP stringer skin structures. This model is employed to investigate the distribution and evolution patterns of the magnetic field, temperature field, and residual stress field. The results show that under the influence of an alternating electromagnetic field, the magnetic field strength peaked at 1.45 mT in the component’s edge region. Notably, the simulated magnetic, temperature, and stress field all exhibit significant edge effects, which are intimately tied to the skin effect induced by high-frequency eddy currents. During welding, asymmetric and nearly elliptical high-temperature zones emerge on both sides of the skin’s bottom, with temperatures in proximity to the stringer area notably higher than those farther away. When the current frequency increases from 150 kHz to 250 kHz, the maximum stress of the induction joint increases from 637 MPa to 778 MPa, and the asymmetric stress concentration area at the welding interface expands accordingly. The measured temperature field and stress results are in high agreement with the simulation outcomes, effectively validating the model’s accuracy and applicability. This study offers theoretical backing for process optimization and quality control in the induction welding of intricate CFRTP components.

Poly（aryl ether ketone）（PAEK） thermoplastic composites exhibit exceptional impact resistance and possess significant application potential in the aerospace industry. To address mechanical performance limitations of PAEK composites fabricated through automated in-situ placement, this study systematically investigates the impacts of post-processing parameters-including temperature, pressure and time-on pore elimination and mechanical properties. Utilizing the automated fiber placement, PAEK prepregs are processed into laminates. A viscosity-pressure-time coupling model is formulated through differential scanning calorimetry（DSC）, rheological assessments and mechanical characterizations. The results demonstrate the model predicts reasonably pore elimination across varying process parameters and the critical post-processing temperature is identified as 340 ℃. The pore elimination is facilitated rapidly due to low and stable resin viscosity at 340-360 ℃. The post-processing pressure significantly influences pore removal efficiency, with a critical pressure of 0.7 MPa at 360 ℃ and requiring 60 min for complete pore elimination. Higher pressures lead to only marginal performance enhancements. The time dependency of material performance depends on pressure: at 0.7 MPa and 360 ℃, full pore elimination is achieved within 60 min, whereas at 1.6 MPa, the required time is reduced to 20 min. At 0.7 MPa, 360 ℃ and 60 min, the tensile strength, flexural strength and interlaminar shear strength are 2844, 1653 MPa and 103 MPa, respectively.

Ceramic matrix composites（CMCs）, as outstanding high-temperature structural materials, have found extensive application in aero engines. Consequently, it is crucial to conduct research on high-temperature mechanical property test methods and ascertain these properties to broaden CMC applications in the aerospace sector. The double-in-plane shear test scheme recommended by the national military standard GJB 10311—2021 often results in high calculated average shear stress in the gauge area due to stress concentration at the incision, leading to significant deviations between in-plane shear modulus test results and those of the V-notch shear test. To address this, a novel in-plane shear mechanical property test method has been developed by integrating the digital image correlation method（DIC） with the double-incision shear test. Compared to the V-notch shear test, this method boasts a smaller test fixture and specimen size, making it more suitable for high-temperature in-plane shear testing. To mitigate the impact of stress concentration at the incision, finite element model updating（FEMU） is proposed, constructing an objective function based on the variance between the average in-plane shear strain and numerically calculated strain in the DIC-measured gauge area. This allows for iterative determination of the material’s in-plane shear modulus. For engineering application convenience, the material’s in-plane shear modulus and strength can be obtained by varying the specimen’s incision depth during testing. The feasibility of this test method and the reliability of its results are further validated using SiC/SiC orthogonal laminated ceramic matrix composites. Results indicate that the proposed experimental method can simultaneously determine the in-plane shear modulus and strength of CMCs. The SiC/SiC ceramic matrix composites exhibit typical yield points in their in-plane shear stress-strain behavior, with post-yield shear behavior characterized by linear strain strengthening.

Titanium matrix composites（TMCs）, as a new generation of lightweight and high-performance metals are considered to be one of the most promising structural materials in the fields of aerospace, automotive and other high-tech industries. Compared with conventional micron-reinforced TMCs, nano-reinforced TMCs（NRTMCs）exhibit more significant advantages such as the desirable strength and ductility synergies and thermal deformation capacity. However, the performance potential of NRTMCs has not been sufficiently developed due to the problems of dispersion and thermal stability of the nano-reinforcements. How to introduce nano-reinforcements and maintain their stability during thermal mechanical processing has been a serious challenge for NRTMCs. This paper reviews the research progress of the process features, fabrication methods, microstructure characteristics and mechanical properties, analyses and identifies a series of fundamental issues such as dispersion and heat stability of nano-reinforced material that constrain its development, and proposes the directions for future research. The development directions of future research focus on:（1）interface reaction control and thermal stability design; （2）batch production and low-cost preparation technology; （3）research on special thermal deformation and heat treatment process; （4）tissue configuration design and toughness mechanism and （5）other key mechanical properties research of nano-particulate reinforced TMCs.

This article provides an overview of the latest research status and application prospects of titanium/titanium alloy composite materials, highlighting their advantages in high specific strength, lightweight properties, thermal stability, and wear resistance, which position them as crucial materials in high-tech sectors such as aerospace, military equipment, and medicine. It summarizes research outcomes demonstrating the steady enhancement of mechanical properties, wear resistance, and thermal stability of titanium matrix composites through the addition of reinforcing phases. The review also reveals advancements in various processing technologies that have improved the grain structure and performance of these composites, while pointing out that challenges persist regarding the stability of these materials under high temperature and pressure conditions, as well as the bonding strength at interfaces. These issues necessitate the optimization of reinforcement distribution, bonding methods, and the exploration of novel composite systems. Furthermore, the combination of surface nanotechnology with digital simulation offers new avenues for optimizing the properties of titanium-based composites. Interface reinforcement and thermal stability research are identified as pivotal for future developments. Ultimately, the essay underscores that the enhancement of titanium-based composite properties and innovations in processing technologies are central to realizing their extensive application in extreme environments. This dual focus also constitutes the direction for pushing the boundaries of composite material performance even further.

In the co-curing process of aramid honeycomb sandwich structures with traditional hexagonal core lattice structures, the deformation compatibility of honeycomb with locally varying structures outside the plane is an important factor affecting the internal forming quality of sandwich structures. This article analyzes the out-of-plane local deformation performance of honeycombs using numerical methods by establishing a finite element quantitative analysis model, combining typical structural experimental verification methods, using full-body modeling and elastic mechanics plate bending theory. It explores the influence of key factors such as honeycomb thickness and external pressure on honeycomb deformation, and verifies the local surface fitting method of super-honeycomb deformation limits. The results show that the quantitative analysis model of aramid honeycomb deformation capability, with deflection deformation fitting as the core, has good applicability for predicting the matching state of honeycomb-layered structures. For cases where the slope of the honeycomb deflection fitting curve is less than the transition slope of the layer, honeycomb yield milling has a positive impact on the bonding quality of the transition region of the layer, but different forms of yield milling do not produce significant differences in bonding quality. The relevant results have certain reference value for structural design and process design of honeycomb sandwich structures.

It provides theoretical guidance for the optimization of mechanical properties to research the dynamic shear mechanical properties and microstructural evolution law of laser-cladding Inconel 625（IN625） alloy. A series of dynamic shear experiments are conducted using the split Hopkinson pressure bar（SHPB）at varying ambient temperatures（20, 600, 800 ℃ and 1000 ℃）and strain rates（40000, 60000 s⁻¹ and 80000 s⁻¹）. These experiments aim to establish the dynamic shear stress-strain relationship. Pre- and post-loading morphologies and crystal structures of the alloy are characterized using scanning electron microscopy（SEM）and electron backscatter diffraction（EBSD）. The results show that both the strain rate strengthening effect and temperature softening effect are pronounced in laser-cladding IN625 alloy, with temperature softening effect predominantly influencing its mechanical behavior at elevated temperatures. Compared to the unloaded sample, the dynamic shear test at room temperature lead to the development of a prominent shear texture, with an increase in dislocation density and a decrease in average grain size. Specially, the proportion of small-angle grain boundaries increases from 29% to 85%. Conversely, high-temperature dynamic shear experiments, compared to room temperature loading, weaken the preferred orientation and reduce the dislocation density of the crystals. These high-temperature conditions further decrease the average grain size and lower the proportion of small-angle grain boundaries from 85% to 73.5%.

To address the very high cycle fatigue（VHCF）issue of GH4169 nickel-based superalloy, which is widely utilized in aero-engines, a fatigue specimen subjected to 20 kHz ultrahigh frequency vibration is designed and tested utilizing a piezoelectric ultrasonic fatigue testing system. At room temperature, the P-S-N curves for VHCF of GH4169 nickel-based superalloy are obtained under various survival probabilities of 5%, 50%, and 95%. The experimental findings reveal that the GH4169 material’s curve exhibits a downward trend when the fatigue life attains 10⁷ cycles, indicating the absence of a fatigue limit and the persistence of fatigue failure. Fracture analysis results indicate that the majority of VHCF cracks initiate from the surface or subsurface of the specimen, with both single-source and multi-source cracking observed. The cracking modes encompass surface sliding cracking and non-metallic inclusion-induced sliding cracking.

With advancements in material technology, a surge in research and development has been witnessed for various high-performance materials, including metamaterials, each possessing unique functionalities. However, meeting the demands of high performance has rendered the application of a single material insufficient for achieving the required interface mechanical and functional integration properties. Functionally gradient composite materials have emerged as a pivotal breakthrough to address this issue. This paper introduces the application background, as well as the research and application status of functionally gradient composite materials in foreign countries. Furthermore, based on the prevalent issues in the domestic engineering field concerning functionally gradient composite materials, the challenges faced in their utilization are highlighted. When compared to international advanced levels, the development of functionally gradient composite materials in China encounters three major hurdles. Firstly, the preparation process remains relatively underdeveloped, impeding large-scale engineering applications. Secondly, due to the scarcity of performance evaluation methods, there is an urgent necessity to establish a coupled functional evaluation system. Thirdly, there is a scarcity of proprietary intellectual property rights pertaining to material design and simulation methods, coupled with the absence of a comprehensive database. Consequently, material design still largely relies on the experience of designers. Lastly, suggestions for the future application and development of functionally gradient composite materials are proposed.

The service life of single crystal turbine blades, which serve as pivotal components in aero-engines, is intricately tied to their surface integrity. To fulfill performance standards, these blades typically undergo shot peening to meet for reinforcement. This study meticulously examines the impact of surface morphology and various surface integrity indicators—including roughness, near-surface microstructure, hardness, and residual stress—on DD6 single-crystal superalloy before and after undergoing shot peening treatments of varying intensities (0.15, 0.2 mmA, and 0.25 mmA). Utilizing a surface profilometer, scanning electron microscope, microhardness tester, and stress tester, we comprehensively analyze these factors. The results show that shot peening diminishes the original machining marks on the DD6 superalloy’s surface, with surface roughness escalating from 0.507 μm at 0.15 mmA to 0.883 μm at 0.25 mmA. A gradient plastic severe deformation layer emerges near the surface, its depth progressively increasing from 45 μm at 0.15 mmA to 98 μm at 0.25 mmA. Furthermore, the surface hardness value rises steadily, from 490HV in the original specimen to 738HV at 0.25 mmA, with the hardened layer’s depth also augmenting, from 50 μm initially to 260 μm at 0.25 mmA. Notably, the alloy attains its peak residual compressive stress of approximately –821.2 MPa on the surface when subjected to a blasting intensity of 0.2 mmA.

Near-α high-temperature titanium alloys typically exhibit poor tensile strengths, falling below 1200 MPa at room temperature and 750 MPa at 600 ℃. On the basis of the cluster formula α-{[Al-Ti₁₂]（AlTi₂）}₁₂+β-{[Al-Ti₁₄]（Mo_0.08Si_0.4Nb_0.1Ta_0.32W_0.14Sn_0.96Zr₁）}₅ of Ti65 alloy, this work partly replaces the elements in the β-Ti structures unit and adds Zr instead of Ti to enhance high-temperature stability of β phase. Consequently, the composition formulas of α-{[Al-Ti₁₂]（AlTi₂）}_x+β-{[Al-Ti₁₃Zr₁]（Mo_0.125Si_0.5Nb_0.125Ta_0.5W_0.25Sn_0.5Zr₁）}_（17–x）（x=11, 12, 13 and 14）series alloys are designed by changing the ratio of α and β cluster unit. The as-cast structure of series alloys is in the form of a basket-weave composed of α plates and residual β phase. As the number of β clusters increases, α plates become increasingly finer, and the tensile strength gradually increases. Among them, the room-temperature tensile strength of Ti-5.3Al-2.5Sn-7.6Zr-0.5Mo-0.5Nb-3.8Ta-0.6Si-1.9W（x=11）reaches 1334 MPa, 28% and 21% more than the reported forged IMI834 and as-cast Ti65 alloys. However, the elongation of this alloy is only 1.3%, which is lower than that of forged IMI834 and as-cast Ti65 alloys. The tensile strength is 856 MPa at 600 ℃, 26% and 37% more than forged IMI834 and as-cast Ti65 alloys with the identical elongation.

The resistance welding process of 7075 aluminum alloy（7075AA） and carbon fiber reinforced polyether ether ketone（CF/PEEK） is optimized through the activation of the aluminum alloy surface and its subsequent integration with a thermoplastic layer. A microgroove network is fabricated on the aluminum alloy surface using laser treatment, which notably augmented the mechanical coupling with the polyetherimide（PEI） thermoplastic layer. In contrast, the bonding effectiveness of sandblasted and untreated samples are inferior. Surface analysis conducted via Fourier transform infrared spectroscopy（FT-IR） and X-ray photoelectron spectroscopy（XPS） reveal the formation of Al—O—Si bonds and a silane coupling film transition layer, both of which fortified the interface. In the resistance welded joints, incomplete bonding between the sandblasted/laser-etched aluminum alloy and the PEI layer lead to debonding of the thermoplastic layer, which emerge as the predominant failure mode. The single lap shear strength（LSS） of the sandblasted joint is 10.47 MPa, whereas the LSS of the laser-etched joint attains 15.35 MPa. Following silane treatment, the bonding of the PEI thermoplastic layer is markedly enhanced, resulting in an LSS of 19.03 MPa for the laser-etched and silane-treated joint—a 23.97% increase compared to simple laser etching. At this juncture, the cross-section of the joint exhibites characteristics indicative of heating element fracture, with the failure mode transitioning to interlayer fracture.

To provide technical support for the design of new seamless flexible trailing edge structures, a comparative study of the elastic properties of four novel zero Poisson’s ratio honeycomb structures（sinusoidal-type, V-type, segmented sinusoidal-type and cosine-type）is conducted through theoretical analysis and finite element simulation. A tensile test on the cosine honeycomb is also carried out. Based on this, a flexible trailing edge based on a two-dimensional deformable zero Poisson’s ratio cosine honeycomb was designed, and the bending performance of the cosine honeycomb trailing edge section is simulated and analyzed. The results show that the in-plane elasticity and stress state of the cosine honeycomb structure are superior to other three honeycomb structures. The quasi-linear strain of the cosine honeycomb achieves 27.8%. Excellent bending performance of cosine honeycomb segment can be achieved by parameter adjustment, thereby achieving significant bending deformation of the flexible trailing edge structure. This study can provide references for the design and analysis of novel flexible trailing edge structures.

ZTA15 titanium alloy ingots, containing oxygen levels of 0.08%, 0.12%, 0.16%, and 0.2%（mass fraction）, are produced through the levitation melting technique. The effect of oxygen content on the microstructure and mechanical properties of the alloy is examined using optical microscopy (OM), scanning electron microscopy (SEM), and X-ray diffraction (XRD). The results show that all four ZTA15 structures, varying in oxygen content, are typical Weisberg morphologies. As oxygen content increase, the α-phase bunches shorten and their orientation become more disordered. Furthermore, the widths of the α-slats in the four alloys decrease progressively, measuring 3.92, 3.06, 2.49 μm, and 2.77 μm, respectively. Initially, as oxygen content rose, both tensile and yield strengths of the alloy increase, followed by a decrease, with a concurrent decline in plasticity. Notably, the alloy with 0.16% oxygen demonstrate peak yield and tensile strengths of 1037 MPa and 909 MPa, respectively. However, when oxygen content reach 0.2%, a significant strength reduction is observed, primarily due to the formation of a coarse α-phase structure, resulting in the lowest elongation among the alloys.

Nano-Ag was deposited onto the surface of T-ZnO_w through a process combining dopamine deposition with the chemical reduction of silver, yielding a novel silver-zinc fungicide. The study explored the impact of dopamine deposition duration and silver ammonia solution concentration on the deposition efficacy of nano-Ag, ultimately determining the optimal reaction conditions. The incorporation of this silver-zinc fungicide enhance the antifungal properties of the silicone sealant, without compromising its heat resistance or adhesion. Furthermore, the mold-proof rating of the aged sealant remain at level 1, demonstrating the excellent thermal stability of the T-ZnO_w/PDA/Ag fungicide.

To address the challenge of inconsistent forming quality observed in carbon fiber-reinforced polyaryl ether ketone（CF/PAEK）composites during in-situ automated fiber placement（AFP）, this study introduces a vacuum-assisted in-situ annealing（VIA）process implemented subsequent to layup. The study systematically examines the impact of VIA parameters—specifically annealing temperature and holding time—on various aspects of CF/PAEK unidirectional laminates, including temperature field uniformity, warpage deformation, porosity, crystallinity, and interlaminar properties. Experimental findings reveal that the VIA process facilitates a uniform temperature field, mitigates crystallinity gradients, and progressively diminishes warpage deformation with an increase in annealing temperature, ultimately achieving complete elimination of warpage. Notably, when the annealing temperature surpasses the resin melting point, internal pores formed during the CF/PAEK prepreg or AFP process undergo substantial reduction, resulting in a porosity level of merely 2%. Furthermore, the interlaminar performance exhibits a remarkable enhancement, with an interlaminar shear strength（ILSS）of 64.66 MPa—representing a 58.6% improvement compared to specimens that have not undergone VIA treatment.

This study investigates the performance evolution of T800/polyaryletherketone（PAEK） thermoplastic composites subjected to hygrothermal aging conditions. By meticulously controlling the cooling rate, two distinct types of carbon fiber-reinforced PAEK composites with varying crystallinities are prepared: CF/PAEK-CL（low crystallinity） and CF/PAEK-CH（high crystallinity）. These composites are then systematically examined for their moisture absorption behavior, thermal properties, and mechanical performance in hygrothermal environments. Experimental results reveal that the water absorption of CF/PAEK composites increases progressively over time, with CF/PAEK-CL exhibiting a notably higher moisture uptake rate due to its lower crystallinity. Following hygrothermal aging, the glass transition temperature（T_g） of all samples decreases, with CF/PAEK-CL experiencing a specific reduction of approximately 5%. Thermal analysis further indicates that hygrothermal aging has a negligible impact on the crystallinity of the materials, and notably, the high-crystallinity composite demonstrates superior thermal stability in such environments. Flexural testing results demonstrate that hygrothermal aging has a limited influence on the flexural strength and modulus of CF/PAEK composites, underscoring their robust resistance to the detrimental effects of hygrothermal conditions on flexural mechanical properties. This resilience ensures their long-term stability and reliability in harsh environments. The findings of this study offer pivotal data and theoretical insights, paving the way for the application of CF/PAEK composites in demanding service conditions.

Constant-amplitude fatigue tests were conducted on overlap specimens of 7075/6061 aluminum alloy TIG fillet weldes. Subsequently, detailed finite element models were developed based on both the hot spot stress method and the critical distance method. The range of maximum principal stress variation was from these models as a fatigue evaluation index for further analysis. By combining the results of finite element stress-strain analysis with the S-N curve recommended by the International Institute of Welding (IIW), the fatigue lives of the weld joints under various loadings were estimated. Testing revealed that specimens primarily fractured at the weld toes on the 7075 side. The maximum stress-strain concentration points in the finite element model were located at the weld toe on the 7075 side, aligning closely with the actual fracture locations. By comparing the predicted fatigue lives with the actual test results, it was determined that the hot spot stress method can predict the fatigue life of TIG welds more accurately. After correcting for plate thickness, the prediction errors were within a factor of two in the low-cycle fatigue range. Both the point method and the line method within the critical distance method can predict hot spot stress, but the point method yields more precise results than the line method.

This study investigates the thermal cycling behavior of HVOF-MCrAlY combined with APS-nanostructured YSZ（nYSZ） thermal barrier coatings（TBCs） produced using three commercial MCrAlY powders commonly utilized by gas turbine original equipment manufacturers（OEMs） and maintenance, repair, and overhaul（MRO） companies, within a temperature range from ambient to 1150 ℃. Among the coatings, HVOF-A386-2.5+APS-nYSZ exhibits the longest furnace cycle testing（FCT） life, while HVOF-A9624+APS-nYSZ has the shortest. However, the differences in FCT life among the three TBCs are insignificant. All three coatings fails in a manner similar to conventional HVOF-MCrAlY+APS-YSZ（mYSZ） coatings, primarily due to crack propagation and coalescence in the APS-YSZ layer near the YSZ/MCrAlY interface, resulting from interface separation at mYSZ/nYSZ and mYSZ/mYSZ interfaces. The thermally grown oxide（TGO） layer grows fastest on the HVOF-A9624 surface, whereas the growth rate is slowest on the HVOF-A386-2.5 surface. However, the variations in TGO growth rates among the three coatings are relatively small. It is anticipated that increasing the surface roughness of the HVOF-MCrAlY may strengthen the YSZ/MCrAlY interface, thus mitigating crack propagation and coalescence in the TBC. Additionally, reinforcing the YSZ/YSZ interface can enhance resistance to interface separation and surface cracking. Furthermore, controlling the aluminum（Al） content in the MCrAlY and/or doping alloy elements into the MCrAlY may slow down diffusion, reducing the TGO growth rate and preventing excessive formation of mixed oxides. These strategies may collectively contribute to improving the durability of HVOF-MCrAlY+APS-YSZ TBCs under thermal cycling conditions.

Titanium alloys are widely used in the fields of aviation, aerospace and marine due to their excellent strength, weldability and plasticity. This study focuses on a near-α titanium alloy Ti-6.5Al-2Zr-Mo-V（TA15）, fabricated by selective laser melting（SLM） technology. The impact of laser scanning speed on the macroscopic morphology and microstructure of the TA15 alloy is investigated using a range of analytical methods such as confocal laser scanning microscopy（CLSM）, optical microscopy（OM）, scanning electron microscopy（SEM）, X-ray diffraction（XRD） and energy dispersive spectroscopy（EDS）. The results show that variations in laser scanning speed significantly influence the forming quality of the alloy. Specifically, higher scanning speeds induce discontinuous fluctuations in the melt pool and irregular surface undulations, whereas lower speeds promote porosity formation at the cross-section. Initially, an increase in laser scanning speed enlarges the size of the martensite structure, followed by a decrease, accompanied by a gradual reduction in martensite hierarchy. Low or high laser scanning speeds cause local cracks on the alloy surface, where elemental depletion and enrichment are observed. These findings demonstrate a direct correlation between laser scanning speed and alloy forming quality. These results provide valuable insights for optimizing the process parameters and strategies of SLM for TA15 alloy, thereby facilitating its further promotion and application.

Fatigue tests were conducted on FGH96 flat plates containing a hole at 600 ℃. Utilizing a viscoplastic constitutive model, the stress and plastic strain distributions within these plates were meticulously calculated. Scanning electron microscopy（SEM） was employed to analyze the fatigue failure mechanism. Based on SEM observations and the geometric attributes of the FGH96 plates with holes, the critical fatigue damage and stress concentration coefficient were defined. Subsequently, the CDM（cumulative damage model）was refined accordingly. The findings revealed that, in comparison to conventional fatigue life prediction techniques, the revised CDM model, which incorporates critical fatigue damage and stress concentration coefficients, exhibited enhanced prediction accuracy for the fatigue life of FGH96 flat plates with holes. Notably, all prediction results fell within a ±2 error band.

The mechanical properties and thermodynamic stability of nickel-based single-crystal superalloys are largely dependent on the charateristics of the precipitated phase interface. In this work, density functional theory（DFT）is utilized to investigate the influence of alloying elements, specially Co, Cr, Mo, W, Re and Ta, on the mechanical properties of γ-Ni/γ′-Ni₃Al interface. Following a convergence analysis to the optimal computational model, our findings reveal that Re and W exhibit the most significant strengthening effects within both the γ and γ′ phases. Notably, Re stands out for its substantial enhancement of Young’s modulus（27 GPa and 11 GPa）and shear modulus（16 GPa and 6 GPa） in the γ and γ′ phases, respectively, while Ta demonstrates a unique proficiency in augmenting the bulk modulus of 21 GPa and 14 GPa in the γ and γ′ phases, respectively. Analysis of interfacial tensile properties indicates that the Re-doped system exhibit the highest ideal tensile strength（approximately 25 GPa）and deformation energy（approximately 1.84 J·m⁻²）. Furthermore, the strengthening impact of alloying elements on interface tensile properties diminishes in the order: Re＞W＞Cr＞Mo＞Ta＞Co＞undoped. Analyses of differential charge density and density of states reveal that the strengthening mechanisms of theses alloying elements are attributable to the augmentation in the chemical bonding strength between doped atoms and their nearest-neighbouring host atoms. Electron orbital characteristics indicate that these alloying elements contribute to retarding interfacial fracture by maintaining local structural stability. A series of results provide ideas for the development of novel nickel-based single-crystal superalloys.

Optical microscopy（OM） and scanning electron microscopy （SEM） methods are employed to investigate the effect of various load conditions—including a constant load of 200 MPa, an average stress of 200 MPa with a stress amplitude of 130 MPa, and an average stress of 150 MPa with a stress amplitude of 130 MPa—on the microstructural evolution of DZ411 alloy. The experimental findings reveal that the dendrite structure remains relatively unchanged under high temperatures and stress conditions. When compared to a constant load, DZ411 alloy subjected to cyclic loading exhibits a reduced number of interdendritic pores, which are also smaller in size. In the absence of loading, the γ′ phase undergoes rafting to form a sheet-like structure. Notably, cyclic loading exhibits a more pronounced promotion effect on the rafting growth process of the γ′ phase than directional constant loading. Additionally, cyclic loading facilitates the merging and growth of small γ′ phase particles, leading to the formation of longer sheet structures as more γ′ phases become interconnected. Furthermore, under cyclic loading, the size and morphological differences among γ′ phase particles become more pronounced.

An investigation is conducted into the mechanisms by which varying levels of phosphorus （P） affect the high-temperature properties, particularly the stress rupture properties, of GH4738 alloy. This is achieved through the use of scanning electron microscopy（SEM）, transmission electron microscopy（TEM）, electron backscatter diffraction（EBSD）analysis, and molecular dynamics simulations. Stress rupture experiments reveals that the optimal stress rupture properties of GH4738 alloy are obtained when the phosphorus content is increased from 0.004%（mass fraction） to 0.0091%. Beyond this range, an increase in phosphorus content lead to a decline in stress rupture properties. Further microstructural analysis and molecular dynamics simulations demonstrates that phosphorus tends to segregate at grain boundaries, enhancing the cohesion force and bonding energy of these boundaries. Additionally, phosphorus interacts with carbides at grain boundaries to influence stress rupture properties. Specifically, as the phosphorus content increases from 0.004% to 0.0091%, M₂₃C₆ carbides at grain boundaries gradually transition from a small, discrete distribution to a discontinuous chain-like distribution. This enhances the pinning effect on dislocations, effectively suppressing their movement and resulting in improved stress rupture properties. However, when the phosphorus content reaches a certain threshold, such as 0.019%, the morphology of M₂₃C₆ carbides at grain boundaries changes to a plate-like shape, leading to a decrease in stress rupture properties.

The creep rupture properties of DD419 single crystal superalloys, fabricated at varying pouring temperatures were examined under conditions of 850 ℃/650 MPa, 1050 ℃/190 MPa and 1100 ℃/130 MPa. SEM, EDS and TEM were used to analyze the microstructure and component segregation to study their effects on the durability. The results show that as the pouring temperature decreases, the primary dendrite spacing of the alloy widens, the eutectic content and the number of micropore increase, and the γ′ phase size diminishes. Under high temperature/low stress（1100℃/130 MPa）, the γ′ phase size exerts a more pronounced influence on durability than do micropore and residual eutectic content. The finely dispersed γ′ phase enhances the alloy’s durability under all three test scenarios, with the alloy poured at 1500 ℃ exhibiting optimal durability. At intermediate temperature/high stress condition（1050℃/190 MPa）, the γ′ phase is intersected by numerous dislocations, and dispersed γ′ phase may contribute to dislocation pile-ups. Concurrently, the alloy maintains good elongation at different pouring temperatures; however, as the pouring temperature decreases, section shrinkage decreases under all three test conditions. Pouring temperature has a negligible impact on the the alloy’s fracture morphology. Specifically, the γ′ phase near the fracture surface of the specimen tested under 850 ℃/650 MPa condition remains cubic morphology, with a mixed -mode fracture mechanism. Under other durability parameters, the γ′ phase assumes a rafted configuration, leading to an all-micropore aggregation fracture mechanism.

For the gears of aero-engine accessory system, the complex working environment requires high fatigue resistance and wear resistance on the gear surface. Laser shock peening technology introduces residual compressive stress and high micro-hardness by severe plastic deformation on the material surface. A more uniform residual stress field and hardness distribution are crucial to improve the fatigue life and wear resistance of the parts. Thus, it is an important topic to investigate how to obtain a uniform residual stress field and hardness distribution by optimizing the technical parameters of laser shock peening. In this paper, a four-layer overlapping laser shock peening path scheme is proposed, and the spatial distribution characteristics of residual stress and micro-hardness after laser shock peening are analyzed by the finite element numerical simulation and experiment. Using finite element numerical simulation method, the spatial homogeneous distribution of the residual stress field after the multi-point laser shock peening is studied. The effects of laser energy and impact times on the residual stress and micro-hardness of gear steel are experimentally investigated. The results show that the proposed four-layer overlapping laser shock peening path scheme can obtain a more uniform surface residual compressive stress field. With the increase of laser energy and impact times, the surface residual stress and micro-hardness also increase, but the increase magnitude will decrease, showing a certain saturation trend.

The tribological properties and wear mechanisms of PTFE filled with graphene at mass fractions of 0.5%, 1%, 3%, 5%, and 7% are investigated, and these are compared with those of PTFE filled with the traditional modifier MoS₂ at mass fractions ranging from 5% to 25%（in increments of 5%）. Additionally, a synergistic modification of PTFE with a combination of "graphene+MoS₂" is conducted, focusing specifically on the tribological properties and wear mechanisms of composites containing MoS₂ at a mass fraction of 15% combined with graphene at mass fractions of 1%, 3%, and 5%. The findings reveal that the incorporation of graphene significantly enhances the tribological performance of PTFE and its composites. Notably, the optimal tribological properties are observed when graphene is present at a mass fraction of 5%, exhibiting an average friction coefficient of 0.0763 and a volumetric wear rate of 230.34×10⁻⁹ mm³·N⁻¹·m⁻¹. The predominant wear mode shifts from adhesive wear to fatigue wear under these conditions. When graphene is used in conjunction with MoS₂ for synergistic modification, it effectively addresses the issue of poor compatibility between MoS₂ and PTFE, mitigating the tendency of MoS₂ to be worn away and causing abrasive wear during friction.

As a critical strategic material for aero-engines and industrial gas turbines, the composition/process design, optimization and process control of superalloys remain at the core of industry concerns. The present work focuses on addressing practical challenges in the development and production of superalloys and their components. It identifies key influencing factors in typical processes within the manufacturing workflow and employs a combination of advanced characterization techniques such as synchrotron radiation and high-throughput experimental methods. This integrated approach enables the design and optimization of critical process parameters for superalloy manufacturing, thereby providing foundational support for enhancing process technology, product performance, research and development efficiency, and reducing costs. Taking representative manufacturing processes involving liquid-solid and solid-solid phase transformations as examples, we explore precision tailoring strategies and validation methods for key stages including master alloy melting/remelting, synergistic particle size/morphology control in gas atomization, shrinkage porosity control during casting solidification, powder storage/desorption treatments, powder consolidation through hot isostatic pressing（HIP） and heat treatment procedures. In addition, optimal usage conditions are investigated for auxiliary materials or consumables integral to superalloy production, particularly ceramics, isothermal forging dies and brazing repair materials. Notably, the research on process tailoring reveals significant phenomena: （1）the impact of oxygen existence forms in cast and powder metallurgy alloys; （2）the influence of the initial microstructural state of alloys on the phase transformation temperature during HIP consolidation and heat treatment; （3）the formation and control of abnormal phases and defects in cast, powder metallurgy and additive manufacturing alloys, along with repair materials for brazing and ceramic refractories. The aforementioned findings establish a theoretical foundation for optimizing and tailoring superalloy process parameters and achieving precise manufacturing control, while also providing feasible technical pathways for industrial implementation.

With the upgrading of information security, target stealth and electromagnetic protection, the urgent development of highly efficient wave-absorbing materials is imperative. This paper briefly describes the working principle of wave-absorbing materials, and comprehends the research progress of coated and structural wave-absorbing materials, and finally focuses on the development of fiber hybrid wave-absorbing composites: the fiber arrangement, component regulation and interface design can synergistically enhance the electromagnetic and mechanical properties. Through multi-fiber synergistic design and multi-scale structural optimization, fiber hybrid wave-absorbing composites can realize the coupling optimization of impedance matching and loss mechanism, and have both broadband absorption and mechanical loading characteristics, which promote the development of wave-absorbing materials in the direction of structural and functional integration. Finally, the technological breakthrough of expanding the wave-absorbing frequency band through multi-fiber blending system is summarized, and the future development of a new generation of dual-use wave-absorbing materials with broadband absorption, lightweight and high-strength characteristics around the deepening of the fiber blending mechanism, multi-scale structural design, improvement of the environmental adaptability, multi-functional integration, synergistic control of the fiber orientation and angle of incidence, and the development of high-temperature ceramic-based wave-absorbing materials are prospected.

Carbon fiber reinforced polymer（CFRP）composites has small and hidden damage after low-speed impact, and the existence of damage significantly reduces the bearing capacity and service life of CFRP materials. C-scan represents a conventional ultrasonic imaging method. To address the issue of low imaging precision in C-scan detection of internal damage caused by low-velocity impact in CFRP, gradient operators were employed to process the original images, and transfer learning methodology was utilized to conduct damage classification training on ResNet18 and ResNet50 architectures. To enhance the classification model’s performance, an image reconstruction model（IRM）based on convolutional neural networks was proposed to improve imaging precision. Additionally, a performance metric σ_EOL, based on the structural similarity index（SSIM）, was introduced to validate the level of image quality enhancement. The iterative training results demonstrate that when the iteration count reaches 200, the σ_EOL of different types of impact damage is greater than 1. To further improve imaging precision, the ResNet residual connection concept is incorporated, leading to the development of the ResIRM network. Compared to IRM, ResIRM exhibits enhanced detection precision for different types of impact damage, with an average σ_EOL improvement of 0.85% across all impact types. Furthermore, the gradient saliency heat maps of the classification model processed by ResIRM indicate that ResIRM effectively reinforces the features in damaged regions.

Nanomaterials can greatly improve the mechanical properties and corrosion resistance of epoxy resin, and the use of nanomaterials to modify epoxy resin is an important research direction in the field of coatings. Fusible bonded epoxy resin (FBE) was modified by ZSM-5 molecular sieve, reduced graphene oxide (rGO) and their interaction (ZSM-5-rGO). The effects of FBE on microhardness, adhesion and corrosion resistance were studied. The results show that the microhardness of ZSM-5 modified fused epoxy resin is increased by 44%. The microhardness value of rGO modified fused epoxy resin is increased by 25.7%, and its corrosion resistance is improved from 6421 Ω·cm² to 75371 Ω·cm². ZSM-5-rGO modified fused bonded epoxy resin has good corrosion resistance and improves the binding force with aluminum alloy matrix by nearly two times. When the ratio of ZSM-5 to rGO is 2∶1, the comprehensive modification effect of ZSM-5 on fusion bonded epoxy resin is the best, the microhardness is 38.84, and the binding force with aluminum alloy matrix is 67.5 N.

With the rapid advancement of modern electronic and communication technologies, there is an increasing demand for high-performance electromagnetic wave（EMW）absorbing materials. Materials that combine lightweight properties, high-temperature resistance, and broadband absorption capabilities have become a growing research hotspot. This work proposes a novel strategy for fabricating ceramic metamaterials based on ultraviolet（UV）-curable hyperbranched polysilazane（UV-PSN） precursors. By introducing photosensitive groups into the ceramic precursor monomers and utilizing digital light processing（DLP） 3D printing technology, the synergistic regulation of microstructure and macroscopic morphology is successfully achieved. The fabricated SiCN ceramic metamaterials not only exhibit high-temperature resistance up to 1400 ℃ and tunable dielectric properties but also demonstrate excellent manufacturing precision. In addition, the unique hollow structure design significantly enhances the impedance matching performance of the overall SiCN ceramic material, achieving an effective absorption bandwidth of 3.4 GHz in the X-band. Furthermore, the overall weight of the SiCN ceramic metamaterials is reduced by 79.6% compared to solid structures. This study provides new design concepts and technical pathways for developing multifunctional EMW absorbing materials suitable for extreme environments.

High-temperature microwave-absorbing materials play a crucial role in enhancing the stealth capabilities of hot-end components in advanced warplanes. Among them, Al₂O₃ and Ti₃SiC₂ have a wide range of applications in this field. However, the two powders have poor fluidity after physical mixing, which makes them difficult to use directly for plasma spraying, so secondary granulation is required. In this research, agglomerated powders composed of Al₂O₃ and Ti₃SiC₂ are successfully prepared using centrifugal spray drying. The study indicates the influence of various factors, including slurry solid content, PVA solution content, spray disk rotational speed, inlet air temperature, and outlet air temperature, on the morphology, surface roughness, and particle size distribution of the agglomerated powders.The results show that optimizing the content of solid and PVA in the slurry is beneficial to improve the sphericity and surface roughness of the powder, controlling the rotational speed of the spray disk can effectively control the particle size distribution of the powder, and a reasonable inlet/outlet temperature will help to further improvement of the sphericity of the powder. Optimal conditions for producing high-quality agglomerated powders are: 60% solid content, 3% PVA solution content, a spray disk rotational speed of 40 r·min⁻¹, an inlet air temperature of 250 ℃, and an outlet air temperature of 130 ℃. Under these conditions, the agglomerated powders exhibit high sphericity, low surface roughness, a bulk density of 1.92 g·cm⁻³, a fluidity of 37.1 s/50 g, and a tightly concentrated particle size distribution（D₁₀ = 30.1 μm, D₅₀ = 56.7 μm, and D₉₀ = 90.1 μm）. These powders, obtained through this method, can be directly utilized in plasma spraying and are suitable for large-scale production, thereby holding significant promise for the research and development of high-temperature wave-absorbing materials based on Al₂O₃ and Ti₃SiC₂.