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.

High Mach flight has put forward more stringent requirements for the material and structure design of new generation of high-speed vehicles. This paper reviews the application of ceramic matrix composites（CMCs） in the structural design of aircraft from the aspects of selection, application, and evaluation, and then the future development direction is put forward to provide reference for aircraft ceramic matrix composite structure design. The selection criteria and corresponding preparation methods of CMCs in different application scenarios are comprehensively reviewed, the typical applications of CMCs in aircraft structures are systematically introduced, and the evaluation criteria and ground test methods of the materials under near-service conditions are analyzed. To order to meet the future demands of aircraft, it is necessary to integrate computer-aided optimization technology and innovative preparation methods to enhance the temperature resistance and fatigue performance of CMCs. Developing highly reliable, long-life joining techniques and integrated design solutions will fully leverage the advantages of these materials. Additionally, in-situ characterization techniques under multi-physical field coupling need to be developed to obtain the performance evolution behaviour of CMCs in actual use, providing a reliable basis for the lightweight structural design of aircraft.

High-entropy alloys（HEAs）have attracted considerable attention from the research community as a pioneering alloy design paradigm over the past two decades. They have fundamentally challenged traditional design paradigms and exhibited exceptional mechanical properties and functional characteristics, thereby positioning themselves as promising candidates for significant engineering applications in the future. Recent advancements have unveiled several alloy systems that demonstrate exceptional performance across diverse metrics, including low-temperature fracture toughness, high-temperature strength, impact resistance, radiation tolerance, and fatigue resistance. These qualities render HEAs highly attractive materials for research with substantial application potential in critical domains such as deep space exploration, deep-sea investigations, low-temperature superconductivity, and advanced nuclear energy technologies. This paper will briefly introduce the concept and classification of HEAs, and review the experimental progress of HEAs under various extreme conditions such as extremely low temperatures, high-speed impacts, and high nuclear radiation. We also summarize the strategies for enhancing the strength and toughness of HEAs, and extract the deformation mechanisms and physical and chemical properties of HEAs under different extreme loads. It is foreseeable that the main development direction of HEAs will be to form microscopic fluctuations in chemical composition and construct multi-scalestructural ordering efficiently through fine adjustment of the selection and proportion of alloying elements and optimization of heat treatment processes. For comprehensive studies on HEAs subjected to extreme loads, it is essential to explore their microscopic deformation mechanisms further while proposing innovative strategies designed to address inherent trade-offs between strength and toughness. The integration of state-of-the-art simulation techniques combined with advanced characterization methods will be crucial for improving research efficiency while providing insights into microstructural behavior. Additionally, tailored optimization approaches should be implemented for distinct advantageous systems and phase structures, particularly those capable of activating dislocation movements, twinning, phase transformations and incorporating novel processing methodologies such as additive manufacturing. Finally, conducting more realistic simulation experiments that closely replicate extreme environments along with generating relevant engineering data are vital steps toward accelerating the practical application of HEAs in challenging settings.

The development of supersonic aircraft has created an urgent demand for heat-resistant aluminum alloy that can serve at the temperatures range from 300 ℃ to 500 ℃. However, the high-temperature mechanical properties of heat-resistant aluminum alloys are still unable to meet practical application requirements. Therefore, further research is needed from the aspects of material composition design and microstructure control to improve the comprehensive mechanical properties of heat-resistant aluminum alloys. In this paper, the research progress of heat-resistant aluminum alloys is reviewed from the aspects of microalloying design and eutectic alloys, and the development trend of heat-resistant aluminum alloys is prospected. The article first systematically introduces the development history and research status of Al-Sc, Al-Cu, Al-Si, and Al-Mg heat-resistant aluminum alloys, focusing on the microalloying design ideas of heat-resistant aluminum alloys, as well as the effects of transition metal elements and rare earth elements on precipitation phases, microstructure, and mechanical properties. Subsequently, the development status of heat-resistant eutectic aluminum alloys in Al-Fe, Al-Ni, Al-Ce, and Al-Si systems is comprehensively summarized, with a focus on the important role of rapid solidification technology and additive manufacturing technology in promoting the development of heat-resistant eutectic aluminum alloys. Finally, the main problems faced in the development and application of new heat-resistant aluminum alloys are analyzed, and the development trends of future research on heat-resistant aluminum alloy is discussed from the perspectives of data-driven composition design, high-throughput experimental verification, engineering application research, and standard system construction.

The aircraft engine is considered the “heart” of the aircraft. The development of advanced aircraft engines focuses on achieving a high thrust-to-weight ratio, high efficiency, low fuel consumption, and extended operational life. High-temperature functional coatings, such as thermal barrier coatings（TBCs）, thermal/environmental barrier composite coatings（T/EBCs）, and high-temperature stealth coatings, are applied to critical hot-end components of aircraft engines. These coatings play a significant role in enhancing the service performance, operational life, safety and reliability of the engine. Taking TBCs, T/EBCs, and high-temperature stealth coatings as examples, this paper provides a systematic overview of recent research progress in the design of high-temperature functional coating materials, coating preparation science and technology, and coating performance evaluation and characterization, both domestically and internationally, with a specific focus on the advancements made at Beihang University. Furthermore, challenges and development trends faced by new high-temperature functional coatings of advanced aircraft engines in the future are also discussed. In the future, the research focus of advanced high-temperature functional coatings will shift toward multifunctional composite coatings, enhanced adaptability to extreme environments, and improved process compatibility.

This paper explores the application and development trends of artificial intelligence (AI) technology, particularly machine learning and natural language processing in the field of failure analysis. Failure analysis is a crucial method for ensuring the reliability and safety of equipment, and is widely used in aerospace, automotive manufacturing, electronic devices, and other fields. Traditional failure analysis methods often rely on expert experience, which is time-consuming and laborious. By integrating AI’s powerful data processing capabilities with traditional methods, the accuracy and efficiency of analysis have been significantly enhanced. In terms of failure mode diagnosis, AI can rapidly and accurately identify various fault modes and provide precise diagnostic results. In failure cause diagnosis, AI integrates data from multiple sources to uncover complex failure factors and potential causal relationships, improving diagnostic reliability. In failure prediction, machine learning can accurately forecast material lifespan and strength, reducing experimental time and costs. In failure prevention, AI offers new approaches to effectively reduce the risk of failure and lower product maintenance costs. The paper also looks forward the future development prospects of AI in failure analysis and highlights challenges and recommendations in the areas, such as data quality improvement, model optimization, interdisciplinary collaboration, and ethical and safety issues.

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.

As a typical ceramic matrix composite （CMC）, SiC_f/SiC composite has enormous potential for application in the aerospace field because of the excellent properties such as high specific strength, high temperature resistance, oxidation resistance and good thermal shock resistance. The interphase between fiber and matrix plays a crucial role for protecting fibers, transmitting load and deflecting cracks, resulting in the pseudo-plastic fracture characteristics of SiC_f/SiC composites. The design scheme of interphase significantly affects its microstructural properties, thereby affecting the macroscopic mechanical properties and damage failure modes of SiC_f/SiC composites. In recent years, nano/micro fabrication techniques based on the focused ion beam （FIB）and nano/micro mechanical testing methods based on the nanoindentation are the effective methods to analyze and extract the interphase properties of SiC_f/SiC composites. The existing design schemes of interphase and the influence of interphase properties on toughening mechanism are reviewed. And also the application conditions, advantages and disadvantages of small-scale mechanical testing techniques including single fiber push-out/push-in and micropillar compression are summarized. Finally, the development trend for the research of CMC interphase properties are prospected: further standardizing the testing methods, building a high-temperature testing platform and modeling of testing data.

SiC_f/SiC composites were prepared by melt infiltration（MI）process, chemical vapor infiltration combined with precursor infiltration and pyrolysis（CVI+PIP）process and precursor infiltration and pyrolysis（PIP）process, respectively. The microstructures, compositions and properties of SiC_f/SiC composites prepared by different processes before and after water-oxygen corrosion at 1300 ℃ were characterized by scanning electron microscopy and its accompanying EDS and X-ray diffractometer. The results show that the distributions of oxygen elements of the fracture surface is obviously different in the composites prepared by different processes, and the phases after corrosion are closely related to the preparation processes. The strength retention rate and modulus retention rate of SiC_f/SiC composites prepared by MI process are 84% and 76% after water oxygen corrosion at 1300 ℃ for 50 hours. The strength retention rate of SiC_f/SiC composites prepared by CVI+PIP is 64%, and the modulus is increased by 6%. The SiC_f/SiC composites prepared by PIP process has a strength retention rate of 49% and a modulus increase of 17%. The composite materials prepared by MI process show oxidation mass gain, while the composite materials prepared by CVI+PIP and PIP process show oxidation mass loss, which are mainly related to its microstructures and compositions.

Thermoelectric materials can efficiently and cleanly convert between electrical and thermal energy, offering significant prospects in waste heat recovery and electronic cooling applications. Lead telluride（PbTe）materials were used in thermoelectric power sources for deep space exploration. Lead selenide（PbSe）, a homologue of PbTe, shows potential as a more abundant and cost-effective alternative for mid-temperature thermoelectric power generation. Recently, research in PbSe thermoelectric has shifted from mid-temperature power generation to near-room-temperature cooling, driven by the growing demand for Te-free thermoelectric cooling materials and devices. This paper reviewed the typical optimization strategies used in the research of p-type PbSe, summarized the key research progress in thermoelectric devices based on this material, and highlighted its significant development prospects. Finally, we provide a personal outlook on developing the near-room-temperature thermoelectric performance of p-type PbSe materials and manufacturing high-performance cooling devices, which includes integrating various optimization strategies, optimizing device assembly techniques, identifying suitable contact materials, and developing Te-free thermoelectric devices based on PbSe, with the goal of advancing their application in critical fields such as deep space exploration and laser cooling.

With the global energy transition and increasing environmental requirements, hydrogen-mixed gas turbines as a high-efficiency and low-emission energy conversion equipment has been widely concerned. This paper reviews the development status of hydrogen-mixed gas turbines domestically and internationally, analyzes the characteristics of hydrogen combustion in gas turbines, explores the impact of hydrogen combustion on complex components and the application of high-temperature materials, and analyzes the performance requirements for hot-end component materials operating under high temperature, high pressure, and corrosive conditions, as well as the main challenges and potential solutions in current material development. The effects of water vapor and hydrogen embrittlement during hydrogen combustion on gas turbine alloys and thermal barrier coatings are discussed in detail.Water vapor accelerates the oxidation and corrosion of alloys, leading to a decline in mechanical properties. Furthermore, hydrogen embrittlement significantly affects the toughness and durability of alloys, increasing the risk of crack propagation and fracture. In terms of the problems, future research should focus on multi-field coupling simulations and accelerated corrosion tests, considering the factors such as temperature, pressure, and different atmospheres to establish realistic environment simulators to evaluate alloy and coating performances. Additionally, the combined effects of hydrogen and water vapor on high-temperature alloys and thermal barrier coatings should be emphasized. This includes investigating the diffusion mechanisms of hydrogen in alloys, interactions with lattice defects, and the microscopic processes leading to hydrogen embrittlement. Building oxidation models in high-temperature water vapor environments, clarifying the dissociation and adsorption mechanisms of water vapor at high temperatures, the hydroxylation of protective oxide films Al₂O₃ and Cr₂O₃, and the growth behavior of non-protective oxides（e.g., spinel） are also essential.

As the turbine inlet temperatures of aero engines continue to rise, there is an urgent need to develop a new generation of single-crystal superalloys and their thermal protective coatings for turbine blades. In order to meet the stringent requirements for the comprehensive performance of high-temperature structural materials in the complex service environments of aero engines, the intelligent design research of single crystal superalloys and thermal protection coatings has been gradually carried out at home and abroad in recent years under the promotion of material integrated computational engineering and material informatics. This paper reviews the latest research progress in the design of novel single-crystal superalloys and thermal protective coatings by utilizing multi-scale computational simulations and machine learning methods. The findings confirm that multi-scale computational simulations offer robust theoretical support for understanding the strengthening and toughening mechanisms of single-crystal superalloys, as well as the oxidation resistance and diffusion protective mechanisms of thermal protective coatings. Additionally, the study highlights the reliability and significant potential of machine learning in constructing intrinsic "composition-structure-property" relationship for high-temperature structural materials. This approach paves an intelligent and efficient new pathway for the rapid development of next-generation high-temperature single-crystal superalloys and thermal protective coatings.

Silicon carbide fiber-reinforced silicon carbide ceramic matrix composites（SiC_f/SiC） used in aero-engines are damaged or even failed due to the oxidation and corrosion by high-temperature and high-speed combustion gases. In this work, the gas generation device was used to simulate the complex gas environment in the aircraft engine, and the aviation kerosene mixed with liquid oxygen fuel in a certain proportion was ignited to form a high-temperature and high-speed combustion gas to assess the material. The oxidation test for 10 h and thermal shock test for 1000 cycles in combustion gas environment at 1200 ℃ were conducted on SiC_f/SiC composites respectively. And the protective effect of environmental barrier coating（EBC）on SiC_f/SiC composites was investigated. Uniaxial tensile tests were conducted on SiC_f/SiC composites and SiC_f/SiC-EBC composites after combustion gas environment assessment, and their fracture and cross-section micro-morphologies were observed by scanning electron microscopy. The results show that no significant oxidation of fibers and interphases is found in SiC_f/SiC composites and SiC_f/SiC-EBC composites after oxidation for 10 h in combustion gas environment, and their uniaxial tensile strength decreases by less than 2%. After 1000 thermal shock cycles in combustion gas environment, multiple micro-cracks are formed and oxidative corrosion of the interfacial layer occurs inside the SiC_f/SiC composites, and the uniaxial tensile strength decreases by 41.3%. The EBC coating can effectively protect the SiC_f/SiC composites from oxidation and corrosion of high-temperature gas, and the uniaxial tensile strength of SiC_f/SiC-EBC composites decreases by 16.6% after 1000 thermal shock cycles.

The spot-welding defects of highly alloyed Ni-base superalloy GH4065A were investigated by using SEM and EBSD analysis methods. Effects of the welding defects on fatigue life and fracture behavior were studied by comparing thin plate samples with a central hole that were non-welded, densely welded and sparsely welded respectively. The results show that the lack-of-fusion defect, solidification crack and liquation crack are the main welding defects responsible for significant reductions in low-cycle fatigue life as well as combined low and high cycle fatigue life. These welding defects result in a transition of the fatigue crack initiation site from the inner surface of the central hole in the non-welded sample to the welding spot in the welded sample, leading to 44%-83% reductions in low-cycle fatigue life at 700 ℃/700 MPa. For the combined low and high cycle fatigue conditions（with a stress amplitude of 700 MPa for the low cycle loading part and 100 MPa for the high cycle loading part）, the welding defects not only alter the site at which fatigue cracks initiate, but also make the crack propagation mode more intergranular. This results in dramatic decreases of over 85% in the fatigue life of welded samples at both 600 ℃ and 700 ℃. Due to shorter distance between the welding spot and the central hole, densely-welded samples exhibit a slightly lower level of fatigue life under low-cycle loading conditions compared to sparsely welded samples. However, the fatigue life difference between them becomes negligible when subjected to combined low and high cycle loadings.

The types, preparation methods, thermal and mechanical properties of rare earth hafnate materials and their corrosion behaviors exposed to low melting point silicate（CMAS） and high temperature water vapor are summarized. The previous investigations indicate that the rare earth hafnates have the characteristics of low thermal conductivity, excellent high-temperature phase stability and good resistance to CMAS corrosion, which shows a favorable application prospect in the field of thermal/environmental barrier coatings（T/EBCs）. However, in order to overcome the limitations of a single-phase rare earth hafnate exposed to water vapor corrosion and CMAS, it is still necessary to carry out systematic studies on multi-rare earth components/high-entropy rare earth hafnate in the future, and further clarify the mechanism of influence of lattice distortion caused by components on physical and chemical properties of materials. Moreover, the coupled control method of thermal, mechanical and chemical properties of hafnate with integrated functions such as thermal protection, water vapor corrosion resistance and CMAS resistance and their corresponding material preparation processes should be explored.

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.

The manufacturing process of composites is crucial for ensuring structural efficiency and application reliability of their products. Computer-based process simulation plays a significant role in improving the manufacturing quality of composite components and reducing the manufacturing cost. Traditional process simulation relies on physical and chemical mechanisms in manufacturing of composites with the mathematical equations solved by numerical methods such as finite element/finite volume analysis and computer-aided design methods e.g. computer graphics. At present, it has been widely used in simulations of the lay-up of reinforcements/prepregs, the infiltration flows of resin, the curing behaviours of thermosetting resin, the heat transmission and exchange, and the nonlinear mechanics including residual stress and curing deformation predictions. Recently, artificial intelligence（AI）technologies have rapidly developed, its technical basis machine learning（ML）, in combination with artificial neural networks（ANN）, has been used in the field of lay-up process of fiber reinforcements, liquid molding processes, and autoclave processes, which aimed for data mining and developing reduced-order models. The former can establish relationships between process conditions and the curing quality or mechanical properties of the composite parts, while the latter can improve computational efficiency of the process simulation. However, due to the complexity, immeasurability, and high cost of manufacturing fiber-reinforced resin matrix composites, at the beginning of the AI age, it is difficult to meet the requirements of ML only by relying on the amount of data obtained by experiments. Also, data-driven AI technology faces uncertain issues regarding the representativeness, generalisability, and interpretability of the models. Therefore, traditional process simulation based on physicochemical mechanisms can provide a large amount of reliable data for data-driven ML simulation, and then through AI, more quantitative models describing the composite process can be established to expand the computable scope of process simulation. At the same time, as AI technology enhances the computational efficiency, the process simulation that meets real-time requirements can evolve into digital twins（DT）of the composite manufacturing process, which can provide new technical support for reducing the composite costs and improving the scientific whole-life cycle management.

The dovetail of ceramic matrix composites（CMC）turbine blade is the key to the assembly and ability to withstand centrifugal loads of the blade. In order to study the mechanical behaviour of the blade dovetail prepared by the melt infiltration（MI）method under the tensile load in the radial direction of rotating, and verify the influence of the internal quality of the dovetail on its static tensile strength and failure mode, the CMC high pressure turbine dovetail element specimens were designed and fabricated, and a uniaxial static tensile test was conducted, the internal quality of the test specimens was scanned using non-destructive X-ray CT. The test process was monitored using DIC and acoustic emission method. The results show that the CMC dovetail is able to maintain in complete contact under uniaxial static tensile loads, and its static strength and failure are very sensitive to its internal quality, especially to the delamination defects. When there are no delamination defects in the dovetail, the damage generally starts from the neck and quickly spreads, the damage starting load is near the maximum fracture load, and the fracture surface is zigzag. When there are delamination defects in the dovetail, the fracture starts from the defects, and the delamination gradually spread and cause the fracture surface of the dovetail, the damage starting load is decreased by 99.05%, and the maximum failure load is decreased by 14.29% compared to the case of no delamination defects, and the fracture surface is consistent with the delamination defects.

Rare earth permanent magnet materials are widely applied in critical fields such as aerospace, energy technology, and transportation, serving as critical materials in modern technology. The 1∶12-type（ThMn₁₂）SmFe permanent magnet material exhibits magnetic properties comparable to Nd₂Fe₁₄B and possesses a higher Curie temperature. It exhibits the highest theoretical magnetic energy product among permanent magnets. Moreover, it consists of abundant elements, showing significant potential for application. However, this material faces challenges in thermal stability, leading to low coercivity, thus hindering its potential. This paper first analyzed the reasons for the poor thermal stability of the 1∶12 phase, concluding the influence of elements occupying different crystallographic sites on phase stability and intrinsic magnetic properties. Subsequently, we analyzed the key factors affecting the coercivity, elucidating the inherent relationship between preparation processes and coercivity. Finally, we proposed strategies for achieving high magnetic energy products in 1∶12 type SmFe permanent magnets, such as multi-site element Co-doping, control of cooling rate, and grain boundary encapsulation, providing important references for developing rare earth permanent magnets.

High-energy photons in space environments, such as X-rays, thermal neutrons, and gamma rays, can cause ionization in polymer materials, leading to covalent bond breakage and degradation reactions. These reactions result in effects such as embrittlement, loss of elasticity, flaking, softening and stickiness, loss of mechanical strength, and gas emission, which can cause temporary damage or permanent failure of aerospace materials or devices. Rare earth elements have excellent radiation resistance to neutrons, high-energy photons and gamma rays due to their high absorption cross sections and atomic numbers. The photoelectric effect, Compton effect and electron pair effect of rare earth elements are firstly introduced in this paper. Next, the domestic and international research progress on the radiation resistance of rare earth elements in polymer materials, including fibers, plastics, rubber, epoxy resins, polyvinyl alcohol (PVA), and chitosan are reviewed. The discussion covers the incorporation of rare earth elements through doping, nanomaterial formation, and organic salts, utilizing preparation techniques such as co-precipitation synthesis, copolymerization, blending and extrusion, and molding. Testing methods include cobalt irradiation, neutron radiation, Monte Carlo simulations, and MCNP program calculations for neutron shielding. Comparative results with heavy metal lead demonstrate that rare earth elements significantly enhance the radiation resistance of polymer materials. Given their non-toxic and lightweight advantages, rare earth elements are expected to replace heavy metals like lead in applications within the medical, nuclear, and aerospace industries. The paper also provides a forward-looking perspective on the development of rare earth-based radiation-resistant polymer composite shielding materials in space environments.

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.

To address the challenges posed by the time-consuming nature of fatigue test and the scattered nature of test data, it is evident that P-S-N curves derived from small samples with high survival rates lack sufficient accuracy, leading to unreliable predictions of fatigue life. The data fusion method based on the performance-life probability mapping principle is used to fuse small sample fatigue data of different stress levels, and the feasibility of obtaining accurate P-S-N curves by this method is analyzed and evaluated. The results demonstrated that P-S-N curves obtained post-fusion are closer to the P-S-N curve derived from larger sample datasets. This approach effectively enhances both reliability and accuracy in predicting fatigue life while simultaneously reducing the amount of required fatigue tests. A comparative evaluation is conducted on the predictive capabilities for fatigue life before and after fusion using different models; notably, it is found that the three-parameter power function model demonstrates superior predictive ability, whereas when ample fatigue data is available, the prediction capabilities among four models（Basquin S-N model, exponential S-N model, three-parameter power function S-N model（based on lognormal distribution）, and three-parameter power function S-N model（based on three-parameter Weibull distribution） exhibit a considerable degree of resemblance.

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.

Main-shaft bearings are vital safety components in aeroengines made of bearing steels with outstanding combinational properties. The material is supposed to exhibit high surface hardness, high fracture toughness, high temperature resistance, fatigue resistance and corrosion resistance. However, under harsh operation conditions bearing steels are prone to rolling contact fatigue（RCF）that leads to bearing failure, severely endangering flight. Therefore, accurately predicting the RCF lives of bearing steels is key to the reliability of aeroengine. This manuscript reviews important results and progress in the RCF and life prediction of aeroengine bearing steels and suggests future research directions. Firstly, special stress state as a result of the Hertzian contact between rolling element and raceway is introduced, where shear stress components peak at the subsurface.This explains the origin of complexsubsurface-originated RCF mechanisms in bearing steels and indicates subsurface-originated RCF to be an important failure mode of bearing steels under ideal conditions. Meanwhile, with increasing contact pressure, the response of material evolves from elastic mode to plastic mode. Besides, due to the harsh service environment of aero-engine bearings, surface-originated also takes place and hence the competition between these two mechanisms is present. Next, three methodologies for RCF life prediction are summarized, being probabilistic models, mechanistic models and numerical models, with their advantages and limitations analyzed. Probabilistic models are well developed and widely employed by industry, but they are in nature a kind of statistical models without accounting for RCF mechanisms and are hence lacking scientificity; Deterministic models predict RCF life via describing physical processes, which are rich in science but poor in accuracy due to their simplification; numerical models balancing both engineering practice and scientific characteristic is a powerful tool to tackle the problem of RCF life prediction, although their accuracy requires further improvement. Finally, it is suggested that future research may focus on solving key scientific problems in RCF, modifying life prediction models via inserting RCF mechanisms and applying artificial intelligence in RCF life prediction.

High-strength aluminum alloys have been widely used in aviation, aerospace and other industries because of their high specific strength and good machining property. Corrosion is an important factor affecting the safety and stability of high-strength aluminum alloys in service. Based on the preparation process of high-strength aluminum alloys, this paper focuses on the effect of structural evolution caused by heat treatment on the corrosion property of high-strength aluminum alloys. The corresponding relationship between the microstructure and corrosion behavior of high-strength aluminum alloys is analyzed. Research directions for improving the corrosion property of high-strength aluminum alloys are proposed. The segregation of elements and phases in high-strength aluminum alloys can easily lead to electrochemical inhomogeneity of microstructure, causing corrosion of substrate. Therefore, based on the optimization of composition, the melt casting process, deformation process and heat treatment process of high-strength aluminum alloys should be regulated to prepare the microstructure with uniform distribution of elements and second phases, and uniform electrochemical property, which is crucial for improving the corrosion property of high-strength aluminum alloys. In addition, the corrosion sensitivity of alloys is affected by the width of the precipitate free zone and the distance and distribution of the grain boundary precipitation phases of alloy. Thoroughly studying and clarifying the effect of various structures such as precipitate free zone on the corrosion behavior of alloys is the prerequisite for the preparation of high-strength aluminum alloys with high corrosion property. To balance the mechanical property and corrosion property of high-strength aluminum alloys, heat treatment methods such as aging and thermomechanical treatment should be optimized, and new composite heat treatment methods should be developed. Meanwhile, the test methods and evaluation methods for the corrosion property of high-strength aluminum alloys are discussed. In order to more efficiently and accurately evaluate the corrosion property and service safety of high-strength aluminum alloys, further research work should be carried out in the combined use of traditional evaluation methods with modern data processing technologies such as digital twin, virtual simulation and machine learning.

Corrosion problem resulting from alternating ambient salt spray and high temperature oxidation poses a great threat to the safe service of aircraft engine during frequent start-stop in marine environment. In the present study, Ni25Cr5AlY coating is prepared on top of GH4169 superalloy substrate by direct-current（DC） magnetron sputtering. Corrosion behavior of the Ni25Cr5AlY coating is systematically studied by designing three different test conditions: high temperature oxidation at 1000 ℃, ambient salt spray, and alternating ambient salt spray and high temperature oxidation. The phase constitution and morphology of the corrosion products are analyzed by X-ray diffraction（XRD） and scanning electron microscopy（SEM）. The results indicate that after 168 h oxidation at 1000 ℃, the coating forms a dense and continuous Al₂O₃ scale which resists well against the oxidizing environment, while the coating suffers from pitting locally after 168 h salt spray test. After 168 h exposure to alternating ambient salt spray and high temperature oxidation test, the Al₂O₃ scale formed on the coating is damaged owing to the chlorine induced active oxidation mechanism, eventually resulting in Cr₂O₃ scale formation. In addition, the Cr₂O₃ scale is porous and cracks locally, which causes accelerated corrosion of the coating and internal oxidation of the coating and substrate. The corrosion degradation of the coating is accelerated under the synergistic effect of salt spray and high temperature oxidation. The GH4169 superalloy without the coating experiences severe scale spallation after 168 h exposure to the alternating test, featured by forming a poorly protective NiO scale with prevalent internal oxidation.

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.

The as-cast microstructure of 2024 high-strength aluminum alloy has an important effect on its thermal workability and end-use performance.The effects of Cu/Mg ratio and solidification rate on as-cast microstructure were investigated by regulating the Cu and Mg content and solidification rate of 2024 alloy. The results show that with the mass ratio of Cu/Mg increases from 2.1 to 4.1, the type of second phase in the alloy is not changed. However, the content of Al₂CuMg gradually decreases, while the content of Al₂Cu and Al₂₃Cu（Fe, Mn） ₄ gradually increases.When the solidification rate increases from 0.2 ℃/s to 2.4 ℃/s, the grain size is obviously refined, the average grain size decreases from 293.0 μm to 77.0 μm. Moreover, the dendrites become developed, and the dendrite arm spacing decreases, and the second phase becomes smaller and distributes more homogeneous in the matrix, and the content of Al₂₃Cu（Fe, Mn） ₄ insoluble phase obviously reduces. The formation of iron-rich insoluble phase can be reduced by reducing the Cu/Mg ratio and increasing the solidification rate, so as that the machining and mechanical properties of the alloy can be improved.

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.

SEM, EBSD and TEM techniques were used to study the effects of grain boundary precipitation characteristics and the Fe-containing second phase（Al₇Cu₂Fe phase） formed under different aging regimes on the intergranular corrosion properties of Al-Zn-Mg-Cu alloys. The results show that the change rate of Fe content of Al₇Cu₂Fe phase with large surface size of aluminum alloy specimen after aging at 120 ℃ for 24 h is the largest, while the phase change rates of Fe content of Al₇Cu₂Fe phase with small size in specimens aging at 120 ℃ for 60 h and 120 h are greater. With the increase of aging time, the corrosion time of surface pitting caused by Al₇Cu₂Fe phase in 7050 aluminum alloy specimen is shortened, and the depth of intergranular corrosion decreases, indicating that its intergranular corrosion resistance is enhanced with the increase of aging time. In addition, with the increase of aging time, the PFZ （precipitation-free zone） width of the sample increases, the number of nuclei of GBPs（grain boundary precipitation） decreases, the spacing between GBPs increases, and the grain orientation prone to intergranular corrosion is gradually concentrated.

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%.

Ceramic fiber sponge with low density, high specific surface area, high porosity, good thermal stability and good thermal insulation performance is expected to become one of the most promising commercial ceramic materials in the fields of heat insulation, flame retardant, water-oil absorption and energy conversion. This paper summarizes the direct assembly methods such as three-dimensional electrospinning, solution blowing spinning and centrifugal spinning, reviews the research progress in the production of ceramic fiber sponge by direct spinning method, analyses the problems of low production efficiency of ceramic fiber sponge, and proposes the future development directions of ceramic fiber sponge: （1）improve the production efficiency, reduce the production cost, and mass produce ceramic fibre sponge with controllable shape; （2）improve the high-temperature thermal insulation performance and promote the application of ceramic fibre sponge in the field of heat insulation; （3）improve the structural stability and produce ceramic fibre sponge with high elasticity, flexibility, and fatigue resistance; （4）research and develop ceramic fibre sponge materials with special functions such as light and electromagnetism, and expand the application range of ceramic fibre sponge.

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 three-layer structure molybdenum-silicon high-temperature oxidation-resistant coating was prepared on selective laser melting Ta10W alloy by slurry sintering process. The microstructure and element distribution of the Ta10W alloy and coating were characterized by SEM and EDS. The tensile properties, microhardness of the Ta10W alloy and coating, and the coating bonding strength were tested. The results show that the coating of selective laser melting Ta10W alloy is divided into three layers: outer, sub-outer and inner layers. The outer layer is TaSi₂ and MoSi₂ phases, the sub-outer layer is TaSi₂ phase and dispersed Ta₅Si₃ phase, and the inner layer is Ta₅Si₃ phase. The yield strength, tensile strength and uniform elongation of the coating and remove coating specimens are 639, 647 MPa, 13.6%, and 602 MPa, 675 MPa, 22.7%, respectively. Compared to the Ta10W alloy specimen, the uniform strain of the remove coating specimen is increased by 5.5%. The reason for this is that the thermal effect in the coating preparation process eliminates the residual stress of the Ta10W alloy formed by selective laser melting. The yield strength of the coated specimen is increased by 37 MPa due to the application of the coating. The microhardness of the outer layer, sub-outer layer, inner layer and Ta10W alloy were 550HV_0.2, 1120HV_0.2 , 534HV_0.01 and 307HV_0.2, respectively. The average coating bonding strength is 63 MPa, which is higher than that of the ceramic and high entropy alloy coatings. This is due to the fact that the three-layer coating has a good metallurgical bond to the Ta10W alloy.

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.

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.

Carbon materials have high specific surface area, high dielectric constant, and excellent thermal and electrical conductivity characteristics, and BaTiO₃ has excellent dielectric properties. The combation of the two materials can effectively prevent and control electromagnetic pollution. In view of this, the BaTiO₃/PAN nanofiber film was prepared by electrospinning method, and then the BaTiO₃/carbon nanofiber mesh composite absorbing fabric was obtained by pre-oxidation and high temperature carbonization treatment. The nanofiber film prepared has the advantages of light, thin and wide bandwidth absorption. The results show that 2.0% BT/C has the best comprehensive performance, the carbon fiber arrangement is dense, the BaTiO₃ crystal form is complete and well dispersed, and the reflection loss at 2.3 mm reaches −61.72 dB, and the maximum absorption bandwidth reaches 8.5 GHz, which has excellent wave absorption.

Grain refinement plays an important role to enhance the mechanical properties of magnesium alloys. In this work, graphene-reinforced AZ91 composites were successfully prepared by pre-dispersion combined with gravity casting method. The microstructure of the GNP/AZ91 composites was characterized using OM, SEM, TEM, etc. The results show that the grain size of AZ91 alloy gradually decreases with the increase of GNP content. When 1% GNP is added, the grain size of AZ91 alloy is reduced from 415 μm to 86 μm, with the refinement efficiency of 79%. It is found and revealed through TEM observation that the refining mechanism of GNP on AZ91 alloy is mainly Al₄C₃ phase obtained by in-situ reaction of GNP with Al element in AZ91 melt, which can promote the heterogeneous nucleation of α-Mg grains, thus achieving significant grain refinement effect. When the GNP content is increased to 0.5%, the best mechanical properties are obtained for AZ91 alloy with the UTS, YS and EL reaching 150, 96 MPa and 2.1%, the improvement of 34%, 32% and 91% respectively compared to AZ91 alloy.