Large-size superhard ceramic balls are increasingly employed in high-end precision bearings and critical transmission systems, owing to their superior mechanical properties and wear resistance. However, their high hardness, brittleness, and size effect make it difficult to simultaneously achieve high form accuracy and excellent surface quality during grinding. To address this challenge, this study proposes an efficient ultra-precision manufacturing technology for ceramic balls based on asymmetric variable-curvature grinding, which is designed to improve the uniformity of grinding trajectory coverage and also enhance machining efficiency. A mathematical model of grinding trajectory coverage is first established based on multi-point contact kinematics, and the influence of the V-groove geometry on the material removal uniformity of ceramic balls is systematically analyzed. Three typical groove-structured grinding plates are then designed and fabricated, with which comparative experiments are conducted to investigate their grinding performance under varying ball diameters. The results indicate that when the ball diameter decreases below 41.21 mm, the grinding performance of the conventional rotationally symmetric groove declines significantly, whereas the asymmetric variable-curvature grooves maintain high coverage uniformity and stable material removal, thereby ensuring superior control of sphericity error and surface roughness. Finally, a sphericity error better than 130 nm and a surface roughness below 6 nm are achieved for silicon nitride ceramic balls with a diameter of 41.20 mm, by the proposed asymmetric variable-curvature grinding technology together with optimized process parameters, which provides theoretical and technical support for the efficient ultra-precision manufacturing of high-precision large-size ceramic balls.

Aiming at the problem that the traditional tool cathode bidirectional feed electrochemical machining (ECM) method cannot achieve the full profile processing of the blade body and the two side platforms of the dual-platform blade, an innovative partitioned dissolution full profile ECM method is proposed. The principle of the new method was expounded. The finite element simulation models of the traditional side-wall uninsulated tool cathode, the traditional sidewall insulated tool cathode, and the new method were established. The electric field simulation comparative analysis was carried out. The simulation results show that the taper of the blade platform processed by the traditional side-wall uninsulated tool cathode is relatively large (about 17.6°). The blades processed by both the traditional side-wall insulated tool cathode and the new method have almost no taper. The simulation results also show that in the new method, the tool cathode has a feed component to the side wall platform, which enables the platform to have the highest and most uniform current density. Finally, a comparative experiment of three ECM methods for nickel-based superalloy dual-platform blades was carried out. The results show that the surface roughness of the blade bodies processed by the three processing methods is similar. The surface roughness of the platform of the blade processed by the traditional side-wall uninsulated tool cathode is approximately R_a1.89 μm, and the taper is approximately 15.5°. The surface roughness of the blade platform processed by the traditional side-wall insulated tool cathode is approximately R_a2.77 μm, with almost no taper. The surface roughness of the blade platform processed by the new partitioned dissolution method is approximately R_a0.61 μm, with almost no taper, which proves the feasibility of the method.

This study investigates the influence of cooling methods on residual stresses in wide-chord hollow fan blades made of titanium alloy through a combination of experimental research and finite element simulation. Temperature data from TC4 titanium alloy square plates under various heat transfer conditions were collected, and the interfacial heat transfer coefficient under different conditions was determined using the DEFORM software. High-temperature uniaxial tensile tests were conducted, and the accuracy of the finite element simulation was verified by comparing residual stresses under different cooling methods. The temperature and stress fields of the stress-free state for hollow fan blades were analyzed, and the effects of the two cooling methods on the residual stresses in the component were compared. It was found that residual stresses after cooling primarily distributed within the hollow section of the blade and along the thin-walled edges of the blade body. Furthermore, during air cooling, residual stress values rapidly peaked at the onset of cooling before gradually relaxing throughout the process. In contrast, furnace cooling, with its slower external temperature decrease, did not generate stress peaks during the initial cooling phase. These findings provide guiding principles for the mass production of wide-chord hollow fan blades made from TC4 titanium alloy.

Hot compression tests with a deformation strain of 4% were conducted on a first generation single crystal superalloy DD413 at 25-1230 ℃. Additionally, different solution heat treatments were applied to the samples deformed at 25 ℃. The effects of deformation temperature and solution heat treatment on recrystallization behavior were investigated using stereomicroscopy, electron backscatter diffraction (EBSD), and scanning electron microscope (SEM). The results indicate that recrystallization occurs at 25-1150 ℃. The recrystallized area fraction ranges from 62% to 74% and the critical grain reference orientation difference (GROD) values inducing recrystallization are all below 1°. At 1200 ℃ and 1230 ℃, no recrystallization is observed, accompanied by significantly higher GROD critical values (approximately 5°) and lower geometrically necessary dislocation (GND) densities compared to lower temperature conditions. After solution heat treatment at 1230 ℃, recrystallization is absent. With increasing the solution heat temperature to 1250 ℃, the recrystallized area fraction greatly increases. The differences in recrystallization behavior under various solution heat treatments are closely related to the dissolution of the γ′ phase and γ / γ′ eutectic.

As a critical component of next-generation aero-engines, the blisk offers substantial advantages in thrustto-weight ratio and aerodynamic efficiency owing to its monolithic lightweight architecture. However, under extreme operating conditions, blisk blades are highly susceptible to various forms of damage, including foreign object damage, hightemperature oxidation, and high-cycle fatigue. The inherent monolithic nature of the blisk precludes the replacement of individual damaged blades, resulting in prohibitively high maintenance costs that severely impede its large-scale production and deployment. Blade repair and remanufacturing technology provides an efficient and cost-effective pathway to restore the performance of damaged blades and extend their service life, and has thus emerged as a key enabling technology for the widespread engineering application of blisks. This paper presents a review of the current research status and future development directions of blisk blade repair technology. Building upon an introduction to blade damage typology and repair process workflows, the theoretical methodologies for geometric model reconstruction and aerodynamic performance recovery of damaged blades are systematically analyzed. Subsequently, with a focus on elastic deformation control during blade repair machining, the research advances and existing challenges in elastic deformation prediction and compensation for thin-walled component milling are thoroughly examined. Finally, prospective development trends in damaged blade repair and remanufacturing technology are discussed.

To meet the stringent requirements of high thrust-to-weight ratio engines for turbine blades, obtaining ceramic cores with high precision and reliability is crucial for manufacturing hollow blades. In response to issues such as high shrinkage rates and the difficulty in balancing porosity with mechanical properties in hot-press injection-molded ceramic cores, this paper provides a review of research on SiO₂, Al₂O₃, MgO, and Y₂O₃-based ceramic cores. Focusing on material design approaches—including optimization of raw material particle size distribution, adjustment of mineralizer types, introduction of high-performance fibers, and incorporation of second phase materials—the influence of these strategies on key properties such as shrinkage, porosity, room- and high-temperature strength, and thermal deformation is discussed, along with the underlying mechanisms. The response of different ceramic core systems to the same strategy varies significantly, and the mechanisms for performance enhancement are not universal. By comparing the commonalities and specific characteristics of different material systems and optimization routes, this review aims to offer a theoretical foundation and technical reference for the rational design and process optimization of future high-performance ceramic cores.

Turbine blades in advanced in-service aero-engines operate under harsh conditions of high temperature, high pressure, and strong disturbance, and their cooling performance is directly related to the thermal efficiency and service life of the engine. Due to manufacturing deviations and operational condition fluctuations, the actual cooling effect of blades often deviates from the design value, exhibiting significant uncertainty characteristics, which can easily lead to dispersion of cooling performance and even safety risks during service. Therefore, conducting research on the uncertainty of blade cooling performance is of great significance for improving the reliable operation of the engine throughout its life cycle. This paper reviews the sources of uncertainty caused by manufacturing processes and operational conditions, including typical factors such as casting shrinkage, hole-drilling deviation, blowing ratio fluctuation, and combustion temperature field inhomogeneity. Relevant methods for uncertainty modeling and sensitivity analysis are summarized. The influence mechanism and variation law of geometric and operational deviations on cooling performance are explored, and the coupling characteristics between uncertainty propagation and cooling system response are analyzed. Finally, this paper identifies that current research still faces challenges, including insufficient statistics on real deviations, the coupling mechanism of multi-source uncertainties remaining not fully understood, and the need for improvement in cooling robustness design methods based on uncertainties. Future research should integrate high-precision measurement technology, high-dimensional learning methods, and multi-physics field simulation approaches to deepen the accurate quantitative analysis of uncertainties and establish a robustness design framework for cooling systems with multi-source coupling effects, thereby enhancing the stability of cooling performance throughout the entire life cycle of blades.

To suppress the formation of Al₄C₃ needle-like brittle phase and porosity defects that are prone to occur during the melting welding of SiC particle reinforced aluminum matrix composites and enhance the engineering application value of their welded structures, laser butt welding of 2 mm thick SiC_p /2A14 aluminum matrix composites with SiC volume fraction of 15% and different thicknesses of Ti foil interlayer were carried out. The results show that the interposition of Ti foil of a certain thickness has a significant effect on improving the weld quality of the base material. The weld zone can be divided into the “newly born phases enrichment zone” at the center of the weld and the “mixed zone” away from the center of the weld. With the increase of the thickness of the Ti foil interlayer, the content of the Al₄C₃ needle-like brittle phase in the “newly born phases enrichment zone” gradually decreases, while the content of the new phase TiC gradually increases, and the morphology of TiC gradually changes from dispersed particles to plate-like or network-like. Meanwhile, the tensile properties of the welded joint show a trend of first increasing and then decreasing. When the thickness of Ti foil interlayer is 0.05 mm, the tensile properties of the laser welded joint of SiC_p /2A14 aluminum matrix composites in the as-welded state are the best. The average tensile strength is 263 MPa, the strength coefficient reaches 77%, and the average elongation after fracture is 1.7%. The fracture surface shows a mixed fracture feature mainly characterized by brittle cleavage fracture.

Aerospace engines represent high-end products in the field of advanced equipment manufacturing. As the core component of an engine, turbine blades are subjected to high temperatures during operation, leading to the formation of oil contaminants and deposits on the inner walls of blade gas film pores. To ensure engine performance, these contaminants must be effectively removed. However, due to the presence of solidified oil residues covered by deposits and their strong adhesion to the substrate, existing polishing techniques remain largely ineffective. To address this challenge, a novel polishing fluid and process—based on abrasive water jet polishing—is proposed, consisting of a hydrocarbon solvent, abrasive particles, and a dispersant. This method integrates abrasive jet technology, hightemperature hydrocarbon-based oil removal, and dispersant-assisted stabilization to overcome the limitations of traditional abrasive water jet polishing, such as poor abrasive dispersion stability and low oil removal efficiency. Experimental results show that every 20 ℃ increase in the temperature of the hydrocarbon fluid enhances oil removal efficiency by a factor of 4-5. When alcohol fatty acid esters are used as the dispersant (at a mass fraction of 2.0%) and the abrasive concentration is maintained at 20 g/dm³, the stability of the polishing fluid is significantly improved, leading to enhanced polishing performance. The surface roughness of the blade gas film pore was reduced from 17.205 μm to 7.810 μm. These results confirm the feasibility of the proposed polishing fluid system in improving both the cleaning efficiency and surface quality of blade gas film pores. This study provides an effective technical approach for the cleaning and polishing of complex aerospace components.

Mechanical joining technology for continuous carbon fiber reinforced silicon carbide ceramic matrix composites is key to promoting the application of this composite material in complex thermal structural components in the aerospace field. This study employed the chemical vapor infiltration process to fabricate M5 3DN C/SiC bolts and nuts, systematically investigating their tensile properties at room temperature, 300 ℃, 600 ℃, and 1000 ℃. The high-temperature tensile degradation mechanism was analyzed based on microstructural evolution. The results indicate that pores in the 3DN C/SiC composite primarily occur around the three-dimensional needled layers and within the unidirectional cloth layers.Variations in cutting forces during the machining process led to thread tooth defects. The high-temperature tensile failure modes of the M5 3DN C/SiC bolts mainly included bolt shank fracture and thread stripping. At 1000 ℃, when the tensile displacement reached half of the pitch, matrix cracking occurred and propagated with increasing load. The exposed carbon fibers at the crack sites, subjected to the high-temperature oxidative environment at 1000 ℃, rapidly lost their subsequent load-bearing capacity.

Three-dimensional laser scanning enables the rapid acquisition of geometric data for aerospace products, holding significant importance for establishing digital measurement systems within the aerospace industry. To further enhance the inspection capability of 3D laser scanning systems for complex geometric features, this study focused on the extraction of forming parameters for aircraft surface countersunk holes. The measurement system error was analyzed from the perspective of variations in equipment scanning behavior. Initially, the principle of 3D laser measurement and its process workflow were introduced. Subsequently, the impact of scanning behavior on 3D laser measurement accuracy was investigated, and an error model based on least squares fitting was constructed. Then, point cloud reconstruction techniques were employed to extract countersunk hole parameters, while a strategy utilizing a robotic system was developed to extract parameters under varying scanning positions and orientations. Finally, an experimental study involving countersunk hole parameter extraction with variable scanning positions and orientations was designed to analyze the influence of different scanning behaviors on 3D laser measurement accuracy. The experimental results demonstrated that the measurement system error exhibits a bilinear variation with scanning position and orientation, showing good agreement with the established error model. The derived error model can guide the quality inspection of countersunk hole formation in actual production processes and provide a basis for optimizing system performance.

Carbon fibre-reinforced polymer/metal double-sided countersunk riveted structures can meet the requirements for aerodynamic shape and lightweight joining of aircraft. This paper focuses on two overlapping forms of CFRP/30CrMnSiA high-strength steel and CFRP/2A12 aluminum alloy in actual machine structures, as well as two types of rivets: TA1 pure titanium solid countersunk rivets and Ti45Nb semi-hollow tailpipe countersunk rivets. Pneumatic pressriveting and electromagnetic riveting process tests and quasi-static tensile tests were conducted under different rivet-hole clearances. The mechanism by which riveting process parameters affect the mechanical properties of joints was explained by combining riveting interference behavior and failure modes. The results indicate that increasing the rivet-hole clearances can improve the shear strength of the joint, but excessive clearances may cause the rivet to tilt prematurely and reduce the joining strength. Electromagnetic riveting can increase the peak load by 3.8% to 12.1% compared to pneumatic pressriveting. When using TA1 rivets, the peak load of CFRP/30CrMnSiA high-strength steel joints is about 8% higher than that of CFRP/2A12 hard aluminum alloy joints. After replacing with Ti45Nb rivets, the difference between the two is not significant, and the difference in geometric dimensions is the main reason for the strength difference between the TA1 rivet joint and the Ti45Nb rivet joint.

Large-size superhard ceramic balls are increasingly employed in high-end precision bearings and critical transmission systems, owing to their superior mechanical properties and wear resistance. However, their high hardness, brittleness, and size effect make it difficult to simultaneously achieve high form accuracy and excellent surface quality during grinding. To address this challenge, this study proposes an efficient ultra-precision manufacturing technology for ceramic balls based on asymmetric variable-curvature grinding, which is designed to improve the uniformity of grinding trajectory coverage and also enhance machining efficiency. A mathematical model of grinding trajectory coverage is first established based on multi-point contact kinematics, and the influence of the V-groove geometry on the material removal uniformity of ceramic balls is systematically analyzed. Three typical groove-structured grinding plates are then designed and fabricated, with which comparative experiments are conducted to investigate their grinding performance under varying ball diameters. The results indicate that when the ball diameter decreases below 41.21 mm, the grinding performance of the conventional rotationally symmetric groove declines significantly, whereas the asymmetric variable-curvature grooves maintain high coverage uniformity and stable material removal, thereby ensuring superior control of sphericity error and surface roughness. Finally, a sphericity error better than 130 nm and a surface roughness below 6 nm are achieved for silicon nitride ceramic balls with a diameter of 41.20 mm, by the proposed asymmetric variable-curvature grinding technology together with optimized process parameters, which provides theoretical and technical support for the efficient ultra-precision manufacturing of high-precision large-size ceramic balls.

Aiming at the problem that the traditional tool cathode bidirectional feed electrochemical machining (ECM) method cannot achieve the full profile processing of the blade body and the two side platforms of the dual-platform blade, an innovative partitioned dissolution full profile ECM method is proposed. The principle of the new method was expounded. The finite element simulation models of the traditional side-wall uninsulated tool cathode, the traditional sidewall insulated tool cathode, and the new method were established. The electric field simulation comparative analysis was carried out. The simulation results show that the taper of the blade platform processed by the traditional side-wall uninsulated tool cathode is relatively large (about 17.6°). The blades processed by both the traditional side-wall insulated tool cathode and the new method have almost no taper. The simulation results also show that in the new method, the tool cathode has a feed component to the side wall platform, which enables the platform to have the highest and most uniform current density. Finally, a comparative experiment of three ECM methods for nickel-based superalloy dual-platform blades was carried out. The results show that the surface roughness of the blade bodies processed by the three processing methods is similar. The surface roughness of the platform of the blade processed by the traditional side-wall uninsulated tool cathode is approximately R_a1.89 μm, and the taper is approximately 15.5°. The surface roughness of the blade platform processed by the traditional side-wall insulated tool cathode is approximately R_a2.77 μm, with almost no taper. The surface roughness of the blade platform processed by the new partitioned dissolution method is approximately R_a0.61 μm, with almost no taper, which proves the feasibility of the method.

This study investigates the influence of cooling methods on residual stresses in wide-chord hollow fan blades made of titanium alloy through a combination of experimental research and finite element simulation. Temperature data from TC4 titanium alloy square plates under various heat transfer conditions were collected, and the interfacial heat transfer coefficient under different conditions was determined using the DEFORM software. High-temperature uniaxial tensile tests were conducted, and the accuracy of the finite element simulation was verified by comparing residual stresses under different cooling methods. The temperature and stress fields of the stress-free state for hollow fan blades were analyzed, and the effects of the two cooling methods on the residual stresses in the component were compared. It was found that residual stresses after cooling primarily distributed within the hollow section of the blade and along the thin-walled edges of the blade body. Furthermore, during air cooling, residual stress values rapidly peaked at the onset of cooling before gradually relaxing throughout the process. In contrast, furnace cooling, with its slower external temperature decrease, did not generate stress peaks during the initial cooling phase. These findings provide guiding principles for the mass production of wide-chord hollow fan blades made from TC4 titanium alloy.

Hot compression tests with a deformation strain of 4% were conducted on a first generation single crystal superalloy DD413 at 25-1230 ℃. Additionally, different solution heat treatments were applied to the samples deformed at 25 ℃. The effects of deformation temperature and solution heat treatment on recrystallization behavior were investigated using stereomicroscopy, electron backscatter diffraction (EBSD), and scanning electron microscope (SEM). The results indicate that recrystallization occurs at 25-1150 ℃. The recrystallized area fraction ranges from 62% to 74% and the critical grain reference orientation difference (GROD) values inducing recrystallization are all below 1°. At 1200 ℃ and 1230 ℃, no recrystallization is observed, accompanied by significantly higher GROD critical values (approximately 5°) and lower geometrically necessary dislocation (GND) densities compared to lower temperature conditions. After solution heat treatment at 1230 ℃, recrystallization is absent. With increasing the solution heat temperature to 1250 ℃, the recrystallized area fraction greatly increases. The differences in recrystallization behavior under various solution heat treatments are closely related to the dissolution of the γ′ phase and γ / γ′ eutectic.

As a critical component of next-generation aero-engines, the blisk offers substantial advantages in thrustto-weight ratio and aerodynamic efficiency owing to its monolithic lightweight architecture. However, under extreme operating conditions, blisk blades are highly susceptible to various forms of damage, including foreign object damage, hightemperature oxidation, and high-cycle fatigue. The inherent monolithic nature of the blisk precludes the replacement of individual damaged blades, resulting in prohibitively high maintenance costs that severely impede its large-scale production and deployment. Blade repair and remanufacturing technology provides an efficient and cost-effective pathway to restore the performance of damaged blades and extend their service life, and has thus emerged as a key enabling technology for the widespread engineering application of blisks. This paper presents a review of the current research status and future development directions of blisk blade repair technology. Building upon an introduction to blade damage typology and repair process workflows, the theoretical methodologies for geometric model reconstruction and aerodynamic performance recovery of damaged blades are systematically analyzed. Subsequently, with a focus on elastic deformation control during blade repair machining, the research advances and existing challenges in elastic deformation prediction and compensation for thin-walled component milling are thoroughly examined. Finally, prospective development trends in damaged blade repair and remanufacturing technology are discussed.

To meet the stringent requirements of high thrust-to-weight ratio engines for turbine blades, obtaining ceramic cores with high precision and reliability is crucial for manufacturing hollow blades. In response to issues such as high shrinkage rates and the difficulty in balancing porosity with mechanical properties in hot-press injection-molded ceramic cores, this paper provides a review of research on SiO₂, Al₂O₃, MgO, and Y₂O₃-based ceramic cores. Focusing on material design approaches—including optimization of raw material particle size distribution, adjustment of mineralizer types, introduction of high-performance fibers, and incorporation of second phase materials—the influence of these strategies on key properties such as shrinkage, porosity, room- and high-temperature strength, and thermal deformation is discussed, along with the underlying mechanisms. The response of different ceramic core systems to the same strategy varies significantly, and the mechanisms for performance enhancement are not universal. By comparing the commonalities and specific characteristics of different material systems and optimization routes, this review aims to offer a theoretical foundation and technical reference for the rational design and process optimization of future high-performance ceramic cores.

Turbine blades in advanced in-service aero-engines operate under harsh conditions of high temperature, high pressure, and strong disturbance, and their cooling performance is directly related to the thermal efficiency and service life of the engine. Due to manufacturing deviations and operational condition fluctuations, the actual cooling effect of blades often deviates from the design value, exhibiting significant uncertainty characteristics, which can easily lead to dispersion of cooling performance and even safety risks during service. Therefore, conducting research on the uncertainty of blade cooling performance is of great significance for improving the reliable operation of the engine throughout its life cycle. This paper reviews the sources of uncertainty caused by manufacturing processes and operational conditions, including typical factors such as casting shrinkage, hole-drilling deviation, blowing ratio fluctuation, and combustion temperature field inhomogeneity. Relevant methods for uncertainty modeling and sensitivity analysis are summarized. The influence mechanism and variation law of geometric and operational deviations on cooling performance are explored, and the coupling characteristics between uncertainty propagation and cooling system response are analyzed. Finally, this paper identifies that current research still faces challenges, including insufficient statistics on real deviations, the coupling mechanism of multi-source uncertainties remaining not fully understood, and the need for improvement in cooling robustness design methods based on uncertainties. Future research should integrate high-precision measurement technology, high-dimensional learning methods, and multi-physics field simulation approaches to deepen the accurate quantitative analysis of uncertainties and establish a robustness design framework for cooling systems with multi-source coupling effects, thereby enhancing the stability of cooling performance throughout the entire life cycle of blades.

To suppress the formation of Al₄C₃ needle-like brittle phase and porosity defects that are prone to occur during the melting welding of SiC particle reinforced aluminum matrix composites and enhance the engineering application value of their welded structures, laser butt welding of 2 mm thick SiC_p /2A14 aluminum matrix composites with SiC volume fraction of 15% and different thicknesses of Ti foil interlayer were carried out. The results show that the interposition of Ti foil of a certain thickness has a significant effect on improving the weld quality of the base material. The weld zone can be divided into the “newly born phases enrichment zone” at the center of the weld and the “mixed zone” away from the center of the weld. With the increase of the thickness of the Ti foil interlayer, the content of the Al₄C₃ needle-like brittle phase in the “newly born phases enrichment zone” gradually decreases, while the content of the new phase TiC gradually increases, and the morphology of TiC gradually changes from dispersed particles to plate-like or network-like. Meanwhile, the tensile properties of the welded joint show a trend of first increasing and then decreasing. When the thickness of Ti foil interlayer is 0.05 mm, the tensile properties of the laser welded joint of SiC_p /2A14 aluminum matrix composites in the as-welded state are the best. The average tensile strength is 263 MPa, the strength coefficient reaches 77%, and the average elongation after fracture is 1.7%. The fracture surface shows a mixed fracture feature mainly characterized by brittle cleavage fracture.

Aerospace engines represent high-end products in the field of advanced equipment manufacturing. As the core component of an engine, turbine blades are subjected to high temperatures during operation, leading to the formation of oil contaminants and deposits on the inner walls of blade gas film pores. To ensure engine performance, these contaminants must be effectively removed. However, due to the presence of solidified oil residues covered by deposits and their strong adhesion to the substrate, existing polishing techniques remain largely ineffective. To address this challenge, a novel polishing fluid and process—based on abrasive water jet polishing—is proposed, consisting of a hydrocarbon solvent, abrasive particles, and a dispersant. This method integrates abrasive jet technology, hightemperature hydrocarbon-based oil removal, and dispersant-assisted stabilization to overcome the limitations of traditional abrasive water jet polishing, such as poor abrasive dispersion stability and low oil removal efficiency. Experimental results show that every 20 ℃ increase in the temperature of the hydrocarbon fluid enhances oil removal efficiency by a factor of 4-5. When alcohol fatty acid esters are used as the dispersant (at a mass fraction of 2.0%) and the abrasive concentration is maintained at 20 g/dm³, the stability of the polishing fluid is significantly improved, leading to enhanced polishing performance. The surface roughness of the blade gas film pore was reduced from 17.205 μm to 7.810 μm. These results confirm the feasibility of the proposed polishing fluid system in improving both the cleaning efficiency and surface quality of blade gas film pores. This study provides an effective technical approach for the cleaning and polishing of complex aerospace components.

Mechanical joining technology for continuous carbon fiber reinforced silicon carbide ceramic matrix composites is key to promoting the application of this composite material in complex thermal structural components in the aerospace field. This study employed the chemical vapor infiltration process to fabricate M5 3DN C/SiC bolts and nuts, systematically investigating their tensile properties at room temperature, 300 ℃, 600 ℃, and 1000 ℃. The high-temperature tensile degradation mechanism was analyzed based on microstructural evolution. The results indicate that pores in the 3DN C/SiC composite primarily occur around the three-dimensional needled layers and within the unidirectional cloth layers.Variations in cutting forces during the machining process led to thread tooth defects. The high-temperature tensile failure modes of the M5 3DN C/SiC bolts mainly included bolt shank fracture and thread stripping. At 1000 ℃, when the tensile displacement reached half of the pitch, matrix cracking occurred and propagated with increasing load. The exposed carbon fibers at the crack sites, subjected to the high-temperature oxidative environment at 1000 ℃, rapidly lost their subsequent load-bearing capacity.