Abstract:With the rapid development of aerospace technology，space mechanical systems have put forward higher requirements for lubricating materials.Liquid lubricants are widely used in key components such as spacecraft bearings and gears due to their excellent lubrication performance and adaptability.However，factors such as high vacuum， high and low temperature changes，radiation，atomic oxygen and microgravity in the space environment make traditional liquid lubricants face challenges such as volatile loss， decreased thermal stability and creep during long-term service.This paper reviews the commonly used liquid lubricating materials in space，including perfluoropolyether，silicone oil，polyalkyl cyclopentane，and grease，and also focuses on new liquid lubricating materials，such as low eutectic solvents， magnetic fluids，and liquid metals.Subsequently，the influence mechanism of the space environment on liquid lubricants is analyzed，and future development trends are discussed，including near-zero friction and wear，self-adaptation，solid-liquid composite，and intelligent lubrication systems.Finally， optimization strategies and characterization methods for space liquid lubricating materials are proposed to provide theoretical guidance for designing spacecraft lubrication systems.

Abstract:Among various emerging advanced engineering materials， face-centered cubic （FCC） high-entropy alloys have high potential application in many fields of aerospace due to its advantages of high specific strength， low temperature toughness， wear resistance and corrosion resistance. Laser additive manufacturing has been widely used in the preparation of high-entropy alloys due to its capacity in manufacturing complex structure and highly controllable processing process. This paper mainly introduces the research progress of laser additive manufacturing of FCC high entropy alloys，such as selective laser melting （SLM） and laser melting deposition （LMD）.This paper reviews the microstructure and mechanical properties of FCC high entropy alloys prepared via laser additive manufacturing， as well as the defects that arise during the process and their underlying formation mechanisms. Besides， the post-treatment processes such as hot isostatic pressing，aging，annealing，hot process and homogenization are described.Finally， the opportunities，challenges，and prospects of laser additive manufacturing of FCC high entropy alloys in large-scale components are discussed.

Abstract:Additive Manufacturing （AM） technology has been widely applied in the fields such as aerospace， biomedicine， and the automotive industry due to its high design flexibility and efficient manufacturing capabilities. However， the surface morphology and microstructure of AM-manufactured components significantly affect adhesive performance， limiting their application in multi-material integration and structural bonding. This paper systematically reviews the adhesive properties of additive manufactured surfaces， focusing on the effects of surface roughness， microstructure， and layered structure on adhesive performance. It also discusses strategies to optimize adhesive performance， including surface post-treatment and customized structural design in additive manufacturing. The research indicates that through the reasonable control of AM process parameters and surface modification， adhesive strength can be significantly improved， providing technical support for the high-reliability applications of AM components. This paper aims to provide theoretical and practical references for the in-depth study and engineering application of additive manufacturing bonding technology.

Abstract:Fiber metal laminates （FMLs） exhibit broad application prospects in the aerospace field due to their high specific strength， specific modulus， and excellent fatigue resistance.However，defects such as metal fracture， fiber buckling， and interlayer delamination during forming processes hinder their large-scale applications. This study focuses on the forming performance of FMLs， using TA2/CF/PEEK laminates as the research object. The deep drawing process of rectangular box components was simulated via finite element analysis to elucidate the forming mechanism. The results indicate that a symmetric fiber orientation of （-45/45/-45/45°） achieves superior forming quality： the strain distribution becomes more homogeneous， the stress concentration effect in the adhesive layer is significantly reduced compared to other orientations，and the minimum limiting thinning rate for all components and the optimal uniformity of thickness distribution.Experimental validation confirms the reliability of the simulation results， demonstrating that this layup design effectively enhances the forming quality of rectangular box components. The findings provide a theoretical basis for optimizing the structural design of fiber metal laminates.

Abstract:Addressing the lack of theoretical guidance in screening effective alloying elements for composite interfacial alloying design，a predictive model for interfacial alloying tendencies was developed based on first-principles calculations and machine learning methods.By identifying critical characteristic parameters of alloying elements that influence heterogeneous interfacial properties，this approach accelerates the alloying design of composite materials.In this study，TiB₂/Al composites are taken as a case example，with TiB₂（0001）/Al（111） coherent and TiB₂（0001）/Al（001） semi-coherent interface models being constructed.After adding a series of alloying atoms，first-principles calculations revealed that the variation trends in the interfacial energy for the two types of interfaces were nearly opposite.Specifically，after adding Mg，Ca，Sc，Y，Zr，Ce，and Hf atoms，the interfacial energy of the coherent interface decreased significantly，whereas that of the semi-coherent interface increased substantially.Furthermore，machine learning analysis demonstrated that the variation in the interfacial energy for the coherent interface was primarily governed by the size effects of the alloy atoms （i.e.，shear modulus，Voronoi volume，and atomic radius）.Conversely，for the semi-coherent interface， the variation was dominated by the electronic effects of the alloy atoms （i.e.，work function， electronegativity，and atomic charge）.Therefore，it is revealed that the influence of alloying elements on interfacial energy primarily depends on interfacial structure and atomic properties. The impact degree of alloying elements on the performance of heterogeneous interfaces can be rapidly predicted using the Voronoi volume，shear modulus，and electronegativity of the alloy atoms.

Abstract:A space vehicle is assembled by combining composite material skeleton components and skins.Due to the stress release after the forming and processing of the composite material skin，it deviates from the theoretical surface. When the composite material skeleton components and the skins are assembled，they can not be matched and coordinated. It is necessary to apply an assembly external force to make the skin fit the skeleton for assembly.However，the pre-stress caused by an excessive assembly force will further affect the performance of the space vehicle.In order to ensure the assembly effect of the vehicle，an optimization method for the assembly process of the "Ω" shaped thin-walled skin parts made of composite material is proposed.Through the scanned point cloud data of the skin，an inverse modeling is carried out to construct the geometric model of the skin.Then，a finite element simulation model is established based on this geometric model.By comparing with the test results of multi-working-condition loading，the finite element simulation model is iteratively optimized repeatedly.Finally， based on the optimized finite element simulation model， it is determined that the optimal assembly pressure sequence of the "Ω" shaped composite thin-walled skin parts is first inside and then outside，so that the fitting state of the skin and the profiling base is closer.

Abstract:Ablative wave-transparent coatings play an important role in the thermal protection of the new generation of aircraft antenna windows.However，the application of the existing wave-transparent coatings was limited by their lack of thermal protection performance，adaptability to aerothermal environment and inability to vulacnize at room temperature.To address this issue，a lightweight wave-transparent and ablative thermal protection coating vulacnized at room temperature was developed in this paper.Using silicone resin as matrix and hexagonal boron nitride （h-BN） as porcelain filler，a new coating material was prepared by changing the proportion of h-BN.The effects of h-BN on the phase composition，thermal stability，mechanical properties and wave-transparent properties of the coatings were investigated by X-ray diffraction （XRD），scanning electron microscope （SEM），thermogravimetric analysis （TG），universal testing machine and arc wind tunnel， respectively.The results show that the addition of 12 phr h-BN greatly improves the structural stability of the coating at high temperature and significantly improves the comprehensive properties of the coating.The density of the obtained coating is about 0.63 g/cm³，the elongation at break is 20% to 30%，and dielectric loss tangent is less than 0.025.It has the advantages of light weight，strong toughness and low dielectric，and can achieve the requirements of ablation，thermal protection and wave-transparent in the thermal environment with megawatt high heat flux and surface temperature above 1 200 ℃.

Abstract:This study addresses the technical challenge of achieving lightweight stealth integration in aerospace equipment by proposing an innovative multilayered electromagnetic metamaterial structure based on carbon fiber/ aranmid fiber composites.Through a multi-level impedance matching design，the structure achieves broadband high-efficiency absorption at an ultrathin thickness of 3.3 mm.A hierarchical fabrication process was employed to construct functional metamaterial layers：aramid fiber-reinforced epoxy resin composites served as dielectric materials，while carbon fiber-reinforced epoxy resin composites acted as conductive materials.The NRL Arch method was adopted to characterize the absorption performance of the sample across the 2 to 18 GHz frequency range. Experimental results demonstrate that the multilayered composite metamaterial exhibits two absorption peaks at 7.03 GHz and 9.84 GHz within the optimized frequency band，with a maximum planar reflectivity of -18.82 dB.Furthermore，the sample displays notable directional sensitivity.When the orientation is rotated from 0° to 90°，the planar reflectivity increases by 3 dB.The proposed methodology provides a technically viable pathway for developing next-generation lightweight stealth equipment， offering both theoretical innovation and engineering applicability.

Abstract:This study investigates the thermal residual stress distribution in TA2/PEEK/CF laminates with interlayer micro-pit arrays through thermal release experiments and finite element simulations.The effects of micro-pit depth，diameter，and center distance on thermal stresses in different regions before and after bending forming are systematically analyzed.Key findings include：For unbent laminates， thermal stress initially decreases and then increases with micro-pit depth，while reducing center distance significantly lowers stress.The diameter shows minimal influence，as thermal stress is dominated by thickness-direction changes caused by thermal expansion mismatch.Post-bending，thermal stress in plastic deformation zones increases with reduced center distance，with comparable impacts from depth and diameter.Micro-pits enhance forming accuracy but elevate localized stress due to increased plastic deformation.In elastic deformation zones，thermal stress decreases notably with smaller center distance，while diameter exerts a stronger influence than depth.Stress relief first improves and then deteriorates with deeper pits.Optimized micro-pit parameters （depth 60 μm， diameter 550 μm，center distance 730 μm） effectively mitigate thermal stress in pre-bending layers and post-bending elastic zones，albeit with increased stress in metal layers of plastic zones.The study reveals the dual role of micro-pits in regulating stress distribution and plastic deformation behavior，offering practical insights for optimizing laminate fabrication and micro-pit design.

Abstract:In order to meet the requirements of lightweight， high performance and thermal control function of satellite main structure，this paper studies from the aspects of small satellite cabin structure optimization， load-bearing thermal control integrated design and stand-alone support structure optimization design，and verified by simulation analysis and mechanical test.In this paper，the cabin plate of the main structure of the satellite is optimized by using low density lattice structure，and the cabin plate is directly manufactured as a whole part， which reduces the weight and shortens the development cycle of the small satellite at the same time.The bearing thermal control integrated design of the laser reinforced manufacturing satellite cabin plate is carried out，and the thermal control design such as heat pipe is integrated into the cabin plate to carry out the multidisciplinary optimization design of structural thermal control cooperation.the number of parts and components is greatly reduced， and the integration and lightweight of structural thermal control function are realized. The mechanical simulation analysis and experimental verification of the laser reinforced manufacturing satellite main structure show that the stress of the satellite main structure is less than 140 MPa，and the yield strength of the laser reinforced aluminum matrix composite is about 410 MPa，which still has a large safety margin，which shows that the mechanical properties of the satellite main structure can meet the requirements.The research results can achieve the overall improvement of the performance and functions of the new generation of satellites，such as lightweight，high load bearing and thermal control，directly promote the progress of satellite structure manufacturing technology，and improve economic and social benefits.

Abstract:The additive manufacturing of Al-Mg-Er-Zr high-strength aluminum alloy is achieved by selective laser melting （SLM） technology to meet the demand for structural components.The formation quality of the alloy is optimized by controlling the laser power and scanning speed，and the influence of heat treatment temperature on the mechanical properties of the aluminum alloy is investigated.The results show that the suitable laser power and scanning speed can control the pores and defects，and the density of samples is also improved.The optimal process parameter is as follows：laser power 280 W，scanning speed 1.2 m/s， scanning pitch 0.08 mm，and layer thickness 0.03 mm. In addition，the tensile strength and yield strength of aluminum alloy increase as the heat treatment temperature increases，while the elongation decreases.The maximum tensile strength of the sample exceeds 500 MPa when the heat treatment temperature is 350 ℃ and the holding time is 2 h，and the elongation is greater than 10%.Finally，the high-strength aluminum alloy samples with good appearance and qualified internal quality are obtained，which laies the technical foundation for the application of high-strength aluminum alloys by SLM in aerospace.

Abstract:In order to solve the problem that it is difficult to control the interface between conductive layer and dielectric layer in the process of manufacturing electromagnetic metamaterials by inkjet printing technology，by changing the printing temperature of dielectric material substrate （80，100，120 ℃） and the thickness of conductive layer （5，10，15，20 μm），the interface morphology，interface bonding force and conductivity of conductive layer were tested and characterized，so as to study the influence of interface behavior between conductive layer and dielectric layer. The results show that the interface behavior between the conductive layer and the dielectric layer is affected by multiple factors such as the substrate printing temperature and the thickness of the conductive layer.The continuous increase of the printing temperature of the dielectric substrate will lead to the continuous improvement of the conductivity of the conductive layer， but it will also cause the interfacial bonding force to increase at first and then decrease，mainly because too high temperature will lead to interfacial stress and excessive solidification.Therefore，it can provide the best interfacial bonding behavior when the dielectric substrate is printed at 100 ℃.The increase of the thickness of the conductive layer can lead to the continuous enhancement of electrical conductivity，but on the whole，it leads to the weakening of the interfacial adhesion.When the printing temperature of the dielectric substrate is 100 ℃，the optimal thickness of the conductive layer is 15 μm， the bonding force is classified as grade 1，and the resistivity is 3.27 mΩ·cm.

Abstract:In the manufacturing process of space column conductive slip ring，the molding quality of the ring body assembly affects the insulation performance and electrical transmission stability of the slip ring directly.In order to improve the sealing and insulation reliability of the ring body assembly of the laminated slip ring during the electroplating process，this paper proposes an anti-infiltration process based on semi-curing treatment of insulating spacers.This method includes coating epoxy film on the end surface of the spacer before assembly and performing，and forming a pre-closed structure through axial loading.A special coating tool was designed experimentally，and the film thickness control and bonding performance were systematically analyzed.The effectiveness of the technology was verified by cleaning efficiency，EDS spectrum analysis and component sectioning experiments.The results show that the process significantly improves the sealing performance of the component during the electroplating stage，the cleaning efficiency is increased by about 5 times，and the insulation value between the rings is stably increased to more than 1 500 MΩ. The research conclusion believes that the semi-curing process of insulating spacers has good process adaptability and promotion prospects， provides effective manufacturing process support for high-voltage and long-life space slip rings，and is an effective technical path to improve the manufacturing quality of high-reliability space slip rings.

Abstract:In order to solve the problems of poor quality consistency and low efficiency in the manual riveting of disc slip ring brush components，the research on the automatic riveting process was carried out， and the process scheme of radial automatic riveting was proposed.The drive platform and PLC control system were designed for the brush assembly products，and the operation process was supplemented by special assembly tooling，which could realize the automatic riveting of multiple groups of brush components.The process verification shows that the radial automatic riveting process can accurately ensure the deformation and appearance requirements of the brush assembly， greatly improve the product quality and work efficiency， and has been applied in model products.

Abstract:To enhance the dimensional accuracy and mechanical properties，and reduce the printing time cost of the parts produced by the fused deposition modeling （FDM） process，the three-dimensional models of the dimensional accuracy and mechanical test samples were designed using Creo Parametric 2.0 software，and then sliced and printed.Combined with orthogonal experiments，the influences of printing temperature，speed and layer thickness on the dimensional accuracy of PLA and PETG-ESD drum-shaped test pieces were studied. The conclusion was drawn that the combination of printing speed of 80 mm/s，printing temperature of 210 ℃ and printing thickness of 0.25 mm resulted in the smallest dimensional error.Under the above combination，tensile and compressive tests were conducted on the mechanical test pieces.The experimental results showed that the honeycomb filling method had the highest tensile strength and breaking force among the three filling methods；when the filling rate increased，the tensile strength and elastic modulus of the test pieces significantly improved；when the wall thickness of the model increased， the tensile strength and elastic modulus of the test pieces also increased.In the compressive test，the PETG-ESD material had a higher strength than PLA.

Abstract:In view of the problems of low efficiency，poor consistency，difficult result tracing and safety risk of climbing operation in the phased array ultrasonic detection of the long tube section of the new launch vehicle，the long tube section is selected as the application object in this paper.the research on ultrasonic in-situ automatic detection technology of longitudinal seam in friction stir welding of long tube section of tank is carried out，which is verified by the design and development of automatic detection system and automatic test.The results show that the detection system breaks through the on-site automatic detection technology，and satisfies the synchronous automatic scanning of the longitudinal seam of the cylinder section with a height of 0 to 7.5 m，and the sensitivity reaches Φ 0.4 mm equivalent hole，which realizes the efficient，safe and accurate detection of the internal quality of the longitudinal seam of the long tube section.

Abstract:In order to solve the problems of low testing efficiency and challenging quality control in the radiography testing process of a large-volume magnesium alloy casting with complex structure and large thickness variation，a set of automatic radiography digital imaging testing system was developed by using the design of planar array detector，small focus fixed X-ray machine，multi-degree-of-freedom C-shaped mechanical system，rotary testing platform，automatic loading and unloading system，etc.，and the detection test verification was carried out.The results show that the adopted radiography digital imaging testing process and the developed testing system can ensure that the quality of the detection image meets the requirements of the national standard，It can accurately detect the internal quality defects of the products，significantly improve the testing efficiency，and achieve the rapid and automatic radiography digital imaging batch testing of a certain type of large-volume complex structure casting.The testing method and system can effectively enhance the testing capability of products and provide a feasible reference for solving the radiography testing problems of complex structural castings.

Abstract:As the fundamental building block of composite materials，the mechanical properties of carbon fiber tows play a critical role in material design and engineering applications.To address the issues of variability and dispersion in tow performance，this study conducted fundamental mechanical tests，including tensile strength， tensile modulus， and elongation at break.The test data from three different manufacturers were systematically analyzed using the recommended statistical method of single-environment B-basis values， aiming to comprehensively evaluate the mechanical properties of carbon fiber tows and provide a reliable basis for material selection. The analysis showed that the tensile properties of the tows from all three manufacturers followed a normal distribution，meeting the basic assumptions of statistical analysis.The B-basis statistical results indicated some differences in performance parameters among manufacturers，yet all fell within acceptable engineering ranges，demonstrating adequate application reliability.As a conservative estimate of the lower bound of material properties， the B-basis value effectively reflects the performance characteristics of carbon fiber tows and offers an engineering-relevant reference for the selection and application of composite materials.