- Ei，ESCI收录期刊
- 中国科学引文数据库(CSCD)核心期刊
- 中文核心期刊
- 文摘与引文数据库(Scopus)
- 剑桥科学文摘(CSA)
Microwave absorbing materials（MAM），as a crucial component of radar stealth technology，reduce the radar cross-section of detected targets by absorbing radar waves，thereby lowering the probability of detection. Currently widely applied in the stealth design of various aircraft，naval vessels，and armored vehicles，they effectively enhance equipment survivability and combat effectiveness on the battlefield，making them strategic key materials in the defense sector. Therefore，developing high-performance radar-absorbing materials represents both a research hotspot in advanced materials science and a critical requirement for national defense security. This paper first provides a detailed discussion on the definition，classification，and absorption principles of radar-absorbing materials. It then systematically summarizes the current research status and latest advancements across different types of radar-absorbing materials，analyzing their respective advantages and limitations based on practical application contexts. Finally，focusing on key challenges in the field，it identifies some primary future research directions： deepening the understanding of loss mechanisms，developing novel materials with unique electromagnetic responses，and enhancing engineering design capabilities.
Refractory high-entropy alloys （RHEAs）， owing to their exceptional high-temperature properties， show great potential for use in extreme environments such as aerospace systems. However， the inherent complexity of their multicomponent systems poses significant challenges to the efficiency of conventional alloy design methods. Although additive manufacturing （AM） overcomes some limitations of traditional fabrication routes， its intrinsic non-equilibrium solidification behavior and complex process-parameter space introduce new challenges in microstructural control and property optimization. In this context， machine learning （ML） offers a data-driven paradigm for uncovering the intricate composition-structure-property relationships in RHEAs and provides a powerful tool for intelligent materials design. This review systematically summarizes the latest advances in the application of ML to RHEAs， with particular focus on key issues in AM scenarios. On the one hand， the roles of ML in phase prediction， strength and ductility optimization， and hardness design are discussed. On the other hand， ML-enabled strategies for process-parameter optimization， defect mitigation， and microstructural tailoring in AM are thoroughly analyzed. Despite notable progress， several challenges remain， including the scarcity of AM-specific datasets， the limited generalization capability of process-property models， and the insufficient integration of physical mechanisms. Therefore， establishing standardized databases oriented toward additive manufacturing， developing machine learning models integrated with physical constraints， and constructing an integrated process-microstructure-property optimization framework are key directions for promoting the transition of refractory high-entropy alloys in the field of additive manufacturing from “printable” to “designable”.
Mg-air batteries have garnered significant attention in recent years due to their outstanding advantages， including high theoretical energy density， excellent safety， low cost， and environmental friendliness. However， systematic reviews concerning aqueous Mg-air battery electrolytes remain relatively scarce. The Mg anode is prone to self-corrosion， discharge product accumulation， and severe block effect in aqueous environments. This results in low anode utilisation， suboptimal operating voltages， and pronounced voltage fluctuations， making the electrolyte a critical factor constraining the practical application of Mg-air batteries. To address this， this paper systematically reviews the fundamental properties and key influencing factors of aqueous Mg-air electrolytes， focusing on electrolyte system selection， interfacial control strategies， and additive mechanisms. The review covers the structural characteristics and applicability of chlorinated and chlorine-free near-neutral electrolytes， the regulatory roles of inorganic， organic， and composite additives， and the synergistic effects of anions at the electrolyte/anode interface. Finally， future development directions for aqueous Mg-air electrolytes are proposed， including in-depth understanding of interfacial regulation mechanisms， green design of electrolyte systems， and rapid formulation screening based on machine learning. This paper aims to provide reference for the research and application of high-performance Mg-air battery electrolytes.
MgH2 has become one of the most widely studied hydrogen storage materials due to its high theoretical hydrogen storage capacity， improved safety， and reversibility. However， its application is limited by its high thermodynamic stability and poor kinetic performance. A doping catalyst can effectively reduce the reaction barrier of hydrogen absorption and desorption， thereby accelerating the reaction rate of hydrogenation and dehydrogenation in the Mg-H system. This approach is an effective and simple method to enhance the hydrogen storage performance of MgH2. Transition metals and their oxides have been widely studied because of their excellent catalytic properties. In this review， various types of transition metals and their oxide catalysts are introduced， and their effects on the hydrogenation and dehydrogenation of MgH2 and the catalytic principle are briefly described. Finally， it is concluded that doping with multi-element alloys， multi-component metal oxides， or combinations of metals and metal oxides to utilize the synergistic effects between different metals is an important method for improving catalytic performance. However， the catalytic mechanisms of some transition metals and their oxides remain unclear at present. Deepening the understanding of catalytic mechanisms， especially conducting in-depth investigations at the atomic scale， will provide strong support for the development and application of magnesium-based hydrogen storage materials with better hydrogen storage performance.
Organic liquid electrolytes commonly used in commercial lithium-ion batteries pose potential safety hazards， such as flammability and electrolyte leakage. In comparison， solid-state lithium-ion batteries based on solid polymer electrolytes have attracted extensive attention， due to their high safety and high energy density. In this article， we introduce the structure and ion conduction mechanism of solid polymer electrolytes， especially three modes of polymer segment migration， surface diffusion， and ion hopping. In terms of preparation methods， the principles， preparation processes， and advantages and disadvantages of ex-situ curing and in-situ polymerization curing are analyzed in detail. The ex-situ curing method has a mature process， but there are a few issues， such as poor interface contact and high thickness. The in-situ curing method can achieve excellent interface compatibility and is also compatible with current battery assembly technology. To overcome the problems of low room temperature ionic conductivity and insufficient electrochemical stability of solid polymer electrolytes， various modification strategies， such as polymer molecular structure design， plasticizer addition， polymer blending， nanoparticle filling， and multi-layer design are explored. These strategies aim to reduce polymer crystallinity， construct fast ion channels， anchor anions， and optimize the interface between electrolytes and electrodes. Finally， the review points out the development trend of solid polymer electrolytes in large-scale preparation and application in solid-state batteries， providing references for future research.
Carbon fiber reinforced thermoplastic composites （CFRTP） show great application potential in aerospace and other fields owing to their advantages of light weight， high specific strength， rapid prototyping， and weldability. As a commonly used lightweight metal in the aerospace industry， titanium alloy is a material that can be directly bonded to CFRTP without corrosion defects. Achieving high-performance joining between the two is of great significance for reducing structural weight， cutting carbon emissions， and ensuring the operational safety of equipment. However， due to the differences in their physical and chemical properties， joining the two materials poses numerous challenges. This paper reviews the research progress on the welding of CFRTP and titanium alloy. It summarizes and analyses the process characteristics of various welding technologies， surface treatment methods of titanium alloys， and interface joining mechanisms. Furthermore， it looks forward to the common issues that need to be addressed in the welding of CFRTP and titanium alloys， aiming to provide a reference for the large-scale assembly application of CFRTP/titanium alloy hybrid structure.
Titanium alloys are universally recognized as the prime option for core load-bearing structures in aero-engines， owing to their remarkable blend of high strength， low density， exceptional creep resistance， and outstanding corrosion resistance. The reliability of titanium alloy joints has a direct bearing on the operational safety and service life of aero-engines. Linear friction welding （LFW）， an efficient solid-state joining technique that is precisely tailored to the precision manufacturing requirements of aero-engines， offers substantial benefits such as near-net shaping， minimal welding flaws， and excellent joint integrity. It facilitates the high-quality and consistent bonding of titanium alloy components and plays a pivotal role in the fabrication and repair of complex， integrated components like blisks.This paper centers on the research and application demands of LFW technology for aero-engine components. It provides an in-depth review of the progress in titanium alloy LFW across four key areas： process experimentation， physical simulation， finite element numerical modeling， and post-weld heat treatment. It systematically summarizes the current research status and identifies the existing challenges in each field. Moreover， the paper points out future research directions， including the evaluation of long-term service performance， multi-scale numerical simulations ranging from the microstructural to the macroscopic level， and the optimization of modified LFW process parameters. These efforts are crucial for promoting the wider industrial application of titanium alloy LFW technology.
Particle-reinforced aluminum matrix composites （PRAMCs）， as light-weight and high-performance structural and functional materials， offer broad application prospects in aerospace， weaponry， transportation， and other fields. This paper systematically reviews the main preparation technologies for PRAMCs developed both domestically and internationally， providing a comparative analysis of two major categories of preparation methods， ex-situ and in-situ synthesis， in terms of their process flows， raw materials， microstructural characteristics， and resulting properties， along with their respective technical advantages and limitations. To further achieve the high-quality forming of high-performance PRAMCs components， semi-solid thixoforming technology effectively integrates the near-net-shape advantages of casting and the mechanical performance benefits of plastic forming， compared to traditional casting and plastic processing techniques. It demonstrates significant potential for the near-net-shape forming of complex-shaped， high-performance PRAMCs components. The key prerequisite for semi-solid thixoforming lies in the preparation of semi-solid billets with fine and uniform spherical microstructures. Thus， this paper provides a detailed overview of the primary methods for preparing semi-solid billets， and reviews research progress in related thixoforming technologies for composites and alloys. Finally， future trends for PRAMCs are discussed， focusing on design and development， innovation in preparation processes， and the deepened application of thixoforming technology.
Fused filament fabrication （FFF） technology boasts significant advantages， including high design flexibility， mold-free operation， and the capacity to rapidly construct complex structures， making it a key method for 3D printing of continuous carbon fiber reinforced thermoplastic polymer （CCFRTP）. However， during the actual printing， CCFRTP often experiences a decline in mechanical properties due to insufficient interfacial bonding between the thermoplastic matrix and the continuous carbon fiber reinforcement， as well as a high internal porosity. To address this issue， this paper analyzes two major factors influencing the performance—the resin matrix and the carbon fiber reinforcement. Based on this， it reviews the recent advances in FFF technology， examines the effects of various printing parameters on mechanical properties， along with optimization strategies. Finally， future development directions and application prospects are discussed.
Fiber-reinforced composites，renowned for their high specific strength，high specific modulus，exceptional fatigue resistance，and outstanding corrosion resistance，are extensively utilized across the aerospace，transportation，and energy industries. Nevertheless，under severe service conditions，the latent progression of internal damage can precipitate sudden failure，underscoring the pressing need for effective structural health monitoring （SHM） technologies. This review comprehensively summarizes the latest advancements in this field，conducting a systematic analysis of the principles，performance merits，and principal limitations of both offline nondestructive testing methods （encompassing ultrasound，X-ray/CT，infrared thermography，and acoustic emission） and online monitoring techniques （including surface-mounted strain gauges，piezoelectric and fiber-optic sensors，as well as embedded optical fiber，resistive，and piezoelectric sensors）. Comparative analysis reveals that offline techniques boast high accuracy but are devoid of real-time capability，while online techniques facilitate dynamic monitoring yet are hampered by limited penetration depth and signal interpretation capabilities. Finally，the paper delineates key avenues for future development，such as the co-design of sensors and structures，multifunctional damage sensing，and intelligent signal processing for pattern recognition and predictive maintenance，offering a valuable reference for the intelligent monitoring of composites under complex service conditions.
SiCf/SiC composites have broad prospects for application in aerospace high-temperature components due to their low density， excellent high-temperature mechanical properties， and oxidation resistance. However， residual stresses generated during preparation and service severely restrict their performance. This paper systematically reviews the research progress on residual stresses in SiCf/SiC composites. Firstly， the formation mechanisms of micro-residual stresses and lattice distortion stresses are elaborated， and the coefficient of thermal expansion mismatch， phase transformation volume effect， and process-induced effect are identified as the main causes. Secondly， the principles， advantages， and disadvantages of experimental characterization techniques （including X-ray diffraction， neutron diffraction， Raman spectroscopy， and nanoindentation） and numerical simulation methods （such as finite element method and molecular dynamics） are introduced. Then， the regulation mechanisms of residual stresses on the mechanical properties， environmental stability， and functional characteristics of composites are analyzed， and residual stress regulation strategies through temperature gradient control， interface coating design， and heat treatment are summarized. Finally， it points out that the current frontier challenges include stress dynamic reconstruction in ultra-high temperature oxidation environments， in-situ real-time monitoring of residual stresses under complex loads and thermal cycles， and artificial intelligence-driven residual stress prediction and optimization design.
Additive manufacturing offers a transformative approach to fabricating ceramics for water treatment through precise multi-scale structural control. This paper comprehensively reviews the application advancements of stereolithography and extrusion-based additive manufacturing techniques for fabricating water treatment ceramics in oil-water separation， organic pollutant degradation， and seawater desalination scenarios. However， persistent challenges involve resolution limitations below 100 nm constraining precise separation layers， trade-offs between structural complexity and mechanical integrity causing delamination risks under pressure， and scalability barriers elevating costs. Future advancements will require self-healing smart ceramics enabling autonomous crack repair alongside machine learning-guided co-design strategies to optimize structure-function relationships. This review aims to provide a reference for the research on additive manufacturing of water treatment ceramics， to promote the industrial application of additive manufacturing technology in high-throughput and long-life water treatment ceramics.
The complexity of cavities， randomness of pore distribution， and multi-scale of pore size in porous materials make it difficult to quantitatively characterize pore microstructure. In recent years， fractal theory attracts more attention because of its unique advantages in portraying the self-similarity and multi-scale of complex structures. This paper reviews the development roadmap of fractal theory and its applications on porous materials， analyzes the single and multi-fractal feature extraction and characterization methods for porous materials at different scales， summarizes some advanced engineering material applications based on multifractal optimization， and discusses the research progress in the applications of fractal theory to the characterization of mechanical， thermal and permeability properties of porous materials. During the optimization design and performance characterization process of porous materials based on fractal theory， the main issues and shortcomings including the ambiguity of correlation mechanism between micro structure and macro multi-functional characteristics， and low efficiency and accuracy for prediction models and/or optimization algorithm are pointed out. The development trend and potential engineering applications of fractal theory such as the consideration of cross-scale effect， multi-physics coupling analysis， and optimization strategy based on machine learning are prospected.
In the semiconductor industry， temperature control is of paramount importance， yet numerous research challenges persist， such as the selection of thermal control materials and the design of heat dissipation management systems. The development of flexible electronic films is also a significant challenge. Currently， flexible electronic films based on graphene and carbon nanotubes are hindered by high costs， limiting their widespread application. Therefore， the development of carbon black flexible electronic films with excellent heating performance， a broad temperature regulation range， and suitability for large-scale applications is of considerable significance. To determine the optimal carbon black loading， this study fabricates composite films with varying carbon black contents and conducts a series of tests， including percolation threshold， maximum temperature， rapid thermal response， cyclic heating stability， and tensile performance tests. The experimental results indicate that the percolation threshold of carbon black in the polymer matrix is approximately 20%. The temperature regulation range of the carbon black heating films is between 25 ℃ and 60 ℃. Under a 32 V voltage， films with 50% and 55% carbon black content reaches maximum temperatures of 53.9 ℃ and 60 ℃， respectively. Both films demonstrate not only a broad regulation range but also excellent thermal stability after cyclic heating， along with superior mechanical properties.
K439B nickel-based alloy is a novel high-temperature material capable of operating at 800 ℃， which has been widely used in critical components such as combustion chamber housings for aerospace engines. However， the traditional casting process struggles to meet the high qualification rate requirement for high-precision forming of thin-walled complex components. In this study， laser powder bed fusion （LPBF） technology is used to process samples. By adjusting the laser power （140-220 W） and scanning speed （600-1400 mm/s）， and using characterization techniques including optical microscopy， scanning electron microscopy， and electron backscatter diffraction， the effects of process parameters of LPBF on the relative density and microstructure are analyzed. The processing window （laser power：160-220 W， scanning speed：1000-1200 mm/s） for manufacturing K439B superalloy via LPBF is summarized， and two process parameters （160 W-1000 mm/s and 220 W-1200 mm/s） within the window are selected to process samples for tensile tests at room-temperature and 800 ℃. The results show that irregular pores and Ti-C carbides are prone to form under the 160 W-1000 mm/s （volume energy density（VED） = 66.67 J/mm³） parameter. In contrast， the samples processed under 220 W-1200 mm/s （VED = 114.58 J/mm³） have a uniform microstructure without carbide， whose ultimate tensile strength at room temperature is over 1 GPa and elongation is over 25%. However， at 800 ℃， all LPBF samples exhibit brittleness （with an elongation after fracture of approximately 0.5%）， which is mainly attributed to the lack of γ' phases and dissolution of cellular substructures inside the grains.This study provides process guidance and theoretical support for the engineering application of LPBF fabricated K439B alloy.
This study delves into the impact of positive and negative defocusing distances on the surface quality， densification， and mechanical properties of 316L stainless steel specimens fabricated through laser powder bed fusion （LPBF）. The results show that specimens form with positive defocus outperformed those formed with negative defocus， a phenomenon attributes to the enhanced stability of the molten pool under positive defocus conditions. When the defocusing distance reaches ±3 mm （surpassing the Rayleigh length）， it leads to a sharp decline in laser power density and a substantial deterioration in spot penetration capability. Under these circumstances， incomplete melting of the metallic powder occurs， which undermines the interlayer metallurgical bonding and triggers a proliferation of defects within the specimens， ultimately resulting in a degradation of their mechanical properties. As the defocusing distance increases from -3 mm to 3 mm， the laser power density initially roses and then declines. The laser power density attains at a defocusing distance of +0.5 mm， reaching 61.33 kW/mm². At this optimal condition， the part exhibits superior performance： the upper surface hardness is 200.1HV5， the lateral surface hardness is 206.2HV5， the tensile strength is （647 ± 27） MPa， the yield strength is （525 ± 30） MPa， and the elongation reaches （49.4 ± 3.1）%. An optimal power density input facilitates effective regulation of the molten pool morphology， achieving a dual-process optimization： ensuring adequate melting of the powder while simultaneously suppressing defect generation.
Laser welding is performed on 3 mm thick dissimilar 6063/A356 aluminum alloys， and the welded joints are subjected to two different post-weld heat treatments： direct aging （DA） and solution aging （T6）. The microstructure and mechanical properties of the welded joints are analyzed using optical microscopy， scanning electron microscopy， and transmission electron microscopy， combined with microhardness testing and tensile testing. The results indicate that under appropriate welding parameters， the weld exhibits excellent formation， and the tensile strength of the as-welded joint reaches 192.5 MPa， which is 73.7% of that of the 6063-T6 base metal. After DA treatment， the tensile strength of the welded joint increases to 233.8 MPa， representing a 21.5% enhancement compared to the as-welded joint. Transmission electron microscopy analysis further reveals that after DA treatment， a large number of acicular β" phases precipitate in the heat-affected zone on the 6063 aluminum alloy side. These nano-sized precipitates exhibit a good coherent or semi-coherent relationship with the Al matrix， effectively hindering dislocation slip and significantly enhancing the joint strength. After T6 treatment， the Si-rich eutectic network in the weld seam is fragmented and spheroidized， transforming into a spherical or polygonal morphology. Consequently， although the tensile strength of the joint decreases， its elongation is significantly improved compared to that of the as-welded and DA-treated joints.
The rotating bending fatigue behavior of 9310 steel by vacuum carburization heat treatment is studied， the microstructure and fracture morphology are analyzed. The hardness gradient， surface roughness， residual stress distribution， and inclusion size in the carburized layer are characterized. Based on the Murakami three-dimensional defect model， a fatigue limit prediction method coupling carburized layer hardness， residual stress， inclusion size， and surface roughness is established， thereby revealing effective approaches to enhance the fatigue performance of vacuum carburized specimens. The results show that after vacuum carburizing heat treatment， the carburized layers of specimens tempered at 150 ℃ and 180 ℃ exhibit a dispersed distribution of carbides and uniform， fine martensite， with no oxidation or decarburization on the surface. Cracks mainly originate from non-metallic inclusions. Among them， the specimen tempered at 150 ℃ possesses a higher surface hardness of 755HV， an effective hardened layer depth （d） of 1.20 mm， and a peak residual compressive stress of 465 MPa. Cracks primarily initiate from non-metallic inclusions. The predicted fatigue limits for specimens tempered at 150 ℃ and 180 ℃ are 1275 MPa and 1260 MPa， respectively， which deviate from the measured values（1282 MPa and 1242 MPa） by only 0.5% and 1.4%， indicating that this prediction method exhibits excellent applicability to carburized steel materials. The effective approaches to improve the fatigue performance of vacuum carburized specimens include reducing inclusion size， increasing carburized layer hardness and residual compressive stress， and lowering surface roughness.
This study systematically investigates the non-isothermal curing kinetics of bismaleimide resin EC230R using non-isothermal differential scanning calorimetry （DSC） in conjunction with the Flynn-Wall-Ozawa （FWO） model and the Málek method. The FWO analysis reveals that the apparent activation energy of the resin system exhibits a rapid nonlinear rise when the conversion rate exceeds 0.8. This transition indicates a dynamic shift from a chemically controlled reaction phase to a diffusion-controlled phase. Based on Málek kinetic modeling， the global reaction rate equation is derived to construct the rate equation for the isothermal curing process. This model enables the prediction of curing behavior and conversion rate of bismaleimide resin EC230R at different temperatures. Furthermore， the curing process is optimized using the curing kinetics model of bismaleimide resin， and the thermal and mechanical properties of the cured bismaleimide resin EC230R are characterized and verified via non-isothermal scanning， tensile， and flexural testing. The results show that after curing at 250 ℃， the conversion rate increases by 14%， and the glass transition temperature （T g） of the resin increases by 30%， while the tensile modulus and flexural modulus decrease slightly by 9.8% and 7.2%， respectively. A strong positive correlation is observed among T g， curing temperature， and conversion rate， suggesting that high-temperature curing enhances thermal resistance by increasing crosslink density. However， excessive crosslinking restricts segmental mobility and reduces packing density， leading to modulus reduction. This study provides critical guidelines and experimental validation for optimizing curing processes and developing high-temperature-resistant structural materials based on bismaleimide resins.
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