The ceramic slurry is prepared using alumina and calcium carbonate powder as matrix materials，polyvinyl alcohol solution as a binder，and acetic acid as a dispersant. Different porous alumina-based ceramics are printed by micro-extrusion 3D printing technology. The effects of hole structure and thickness on the sewage filtration performance and its affecting mechanism of porous alumina-based ceramics are investigated. The results show that the multi-layer cross-hole alumina-based ceramic samples with the hole diameter less than 0.1 mm are successfully fabricated by the micro-extrusion 3D printing method with a stepwise 30° filling angle and varying filling rates. The cross hole distribution can divert sewage flow and increase the effective filtration area，while the thicker multi-layer cross-hole porous alumina-based ceramic provides a longer path for sewage filtration，facilitating the removal of small molecular particles in the sewage. When the filling rate is 90% and the ceramic thickness exceeds 8 mm，the sewage turbidity removal rate exceeds 90%，and the filtered sewage turbidity is below 10 NUT，satisfying the industrial and agricultural requirements for water. Based on adsorption，screening-filter cake-deep bed filtration mechanism，a filtration mechanism model of the multi-layer cross-hole and through-hole structures is established. The multi-layer cross-hole alumina-based ceramics with submicron and micron-sized holes perform better in terms of permeability and filtration ability，compared to through-hole alumina filtration ceramics，possessing higher potential for sewage treatment applications. This research provides valuable reference for the application of micro-extrusion 3D printing technology in the field of porous ceramic filtration.

In order to improve the fracture toughness of Y₂O₃ ceramics and realize the preparation of complex structures， Al₂O₃ whiskers （Al₂O_3w） are introduced to toughen Y₂O₃ ceramics， and Al₂O_3w/Y₂O₃ complex ceramic parts are successfully prepared by binder jetting method. The effects of Al₂O_3w content （1%， 3%， 5%，mass fraction，the same below） on the properties of green body forming， sintering densification， and mechanical properties are systematically investigated. The results show that the addition of Al₂O_3w has a little effect on the porosity of the green body， but significantly optimizes the sintering process. When the content of Al₂O_3w is 3%， the porosity of the sintered ceramics is as low as 57.47%， the flexural strength is enhanced to 6.54 MPa. The fracture toughness reaches 2.31 MPa·m^1/2， which is 2.9 times higher than that of pure Y₂O₃. Excessive addition （5%） results in a rise in porosity to 59.47% and a decrease in fracture toughness to 1.54 MPa·m^1/2. Microanalysis shows that Al₂O_3w inhibits crack propagation through the whisker-bridging and crack-deflection mechanism， with an optimal doping amount of 3%.

As a one-dimensional single-crystal material，silicon nitride whiskers possess excellent mechanical，thermal，high-temperature resistance，and corrosion resistance properties，making them a widely used reinforcing material. This paper systematically reviews the current status and application prospects of silicon nitride whisker-reinforced polymer，metal，and ceramic matrix composites. This work introduces the mainstream methods for preparing silicon nitride whiskers，including self-propagating high-temperature synthesis，carbothermal reduction nitridation，direct nitridation，and high-temperature heat treatment. The advantages and disadvantages of each method are analyzed，and the challenges and solutions in practical applications，such as interface bonding and dispersion uniformity，are discussed. Additionally，the paper also provides an outlook on the future development prospects of whisker preparation and application.

With the advancement of high-performance aero-engines and the growing future requirements for intelligent engine design， monitoring the strain of critical components subjected to combined thermal and mechanical stresses has evolved as a vital data source. This data is essential for evaluating material performance during service， enhancing design accuracy， and achieving comprehensive lifecycle management.Indium tin oxide （ITO） thin films have emerged as a preferred material for measuring high-temperature strain in structural materials due to their stability at elevated temperatures，excellent strain measurement sensitivity，and excellent electrical conductivity. This paper expounds on the fundamental principles，basic structures，and preparation methods of resistive thin-film strain gauges，and analyzes and investigates strategies for enhancing the performance of ITO resistive thin film strain gauges，thereby promoting their engineering applications in the aerospace industry.

Phenolic resin materials have a wide range of applications in aerospace thermal protection due to their excellent thermal stability， as well as their low cost and short preparation cycle. By means of chemical and physical modification， more functions or new features can be integrated into phenolic resin matrix composites to make them develop in the direction of high performance and further broaden their application areas. In this paper， the research progress of heat-resistant modification of phenolic resin matrix composites in recent years is reviewed in detail， and the modification methods for synthetic raw materials， molecular structure， and pyrolytic morphology are discussed from the thermal decomposition mechanism. The application prospects are elaborated， and the current problems are analyzed in depth， such as the performance needs in extreme environments still need to be further improved， and the development direction of the high performance and multifunctionality of phenolic resin matrix composites is proposed， and the development direction of further improving its serviceability is discussed. The development direction of high performance and multifunctionalization of phenolic resin matrix composites is proposed， which is of great significance for further improving its service performance and expanding its application scope.

Nanoscale zero-valent iron （nZVI） is used for the reductive degradation of nitrate wastewater due to its advantages， such as abundant elemental content， strong reducibility， and easy recoverability. However， its surface is prone to passivation， making efficient reactions difficult to sustain. The reaction is highly dependent on an acidic environment and has poor selectivity toward target reactants. The products of its reaction with nitrate wastewater are often dominated by toxic ammonia nitrogen. For this reason， numerous researchers have conducted studies focusing on the efficient reaction between nZVI and nitrate wastewater to generate pollution-free nitrogen gas. This paper first elaborates on the mechanism of nitrate wastewater degradation by nZVI alone and highlights its limitations. It then summarizes the enhancement measures to improve the nitrate-degradation efficiency and nitrogen-generation rate of nZVI. The summary shows that the key to improving the nitrate degradation efficiency of nZVI lies in providing sufficient protons and reducing the negative impact of oxides. The main measures to increase the nitrogen yield include three aspects. First is the modification of the chemical properties or structure of nZVI itself. Second is the addition of reducing additives. Third is the coupling with other processes. Finally， this paper comments on and prospects various measures for enhancing the efficient degradation of nitrate wastewater by nZVI.

Al-Si-Mg-Sc-Zr alloys are prepared through phase diagram design and the smelting process. The effect of elemental addition levels on solidification parameters is investigated. Additionally，the room-temperature tensile properties and microstructure of the as-cast alloys are thoroughly analyzed.The results reveal that the as-cast microstructure consists of α-Al matrix， Al-Si eutectic phase， Mg₂Si phase， Al₃Zr phase， and Al₃（Sc， Zr） phase. Silicon has the most pronounced effect on the tensile strength， whereas magnesium primarily influences the secondary dendrite arm spacing（SDAS）. The liquidus temperature gradually decreases with an increase in silicon content， and the solidus temperature continuously drops as the magnesium content rises.With the addition of the Sb element， the morphology of the eutectic silicon phase transforms from needle-like and long-striped shapes to short rod-shaped or worm-shaped forms， and its aspect ratio decreases from 8.19 to 3.31. The fine-sized Al₃Zr and Al₃（Sc， Zr） phases refine the grain size from 272 μm to 224 μm. As a result， the ultimate tensile strength and yield strength reach 211 MPa and 125 MPa， respectively， with an elongation of approximately 5.1%. The enhancement of mechanical properties is attributed to the fine-grained strengthening of the Al₃Zr and Al₃（Sc， Zr） phases， as well as the second-phase strengthening effect of the eutectic silicon phase. As the addition of silicon and magnesium elements increases， the fracture mechanism shifts from a combination of intergranular and dimple fractures to purely intergranular fractures.

Porous metal aluminum， a low-density metallic foam with a porous structure， exhibits good energy absorption and sound absorption properties， leading to its wide application in fields such as machinery manufacturing and aerospace. Currently， the fabrication of porous aluminum primarily relies on physical or electrochemical methods， which often involve complex processes and high costs. This study employs a low-cost material extrusion forming technique to prepare porous metal aluminum， investigates its forming characteristics， and systematically examines the effects of aluminum-based slurry solid content， forming parameters， and sintering processes on the properties of the extruded porous metal aluminum， and the pore structure is optimized to prepare porous metal aluminum. The results show that when the solid content of the aluminum-based slurry is 80%（mass fraction）， the desired billet can be extruded completely without collapse or depression. Using process parameters of a needle diameter of 0.34 mm， a layer height of 0.22 mm， and a filling rate of 50% to prepare the billet. The porous metal aluminum obtained by sintering at 650 ℃ and holding for 150 min has good properties， with a flexural strength of 12.57 MPa， a porosity of 53.96%， and a shrinkage rate of 3.19%， meeting the performance requirements for porous metal aluminum.

The hot isostatic pressing （HIP） technique is employed to create a diffusion-bonded joint between DD15 alloy and SC-4 alloy. This study systematically examines the impact of HIP temperature and nickel electrodeposited coating on the microstructure and elemental diffusion characteristics at the diffusion-bonded joint. The results reveal that HIP diffusion bonding effectively achieves a reliable bond between DD15 and SC-4. Both sides of the bonding interface exhibit distinct element diffusion zones and microstructure affected zones， accompanied by the precipitation of large γ' phases， carbides， and oxides in proximity to the interface. In the DD15 alloy， recrystallization occurs in a region approximately 10-20 μm from the surface. Carbides and large-sized γ' phases are present within this region. In the range of 20-140 μm away from the interface， the γ' phases undergo coarsening. For the SC-4 alloy， carbide redissolution occurs within 30 μm from the interface， and large γ' phases are observed in the vicinity of the interface.As the HIP temperature increases， the microstructure of DD15 within the heat-affected zone remains relatively unchanged， whereas the prominent γ' phase in SC-4 diminishes， and the size of carbides and oxides at the bonding interface augments. The influence of nickel plating is evident， with various shapes of γ' phases （long strip-shaped γ' phase， large γ' phase （>2 μm）， fine γ' phase （200-500 nm）） emerging near the connection interface， accompanied by the disappearance of carbides and oxides. Notably， the large γ' phases in SC-4 also vanish under this condition.

In light of the application scenarios where the combustion chamber and turbine components of aeroengines are repeatedly subjected to short-term overheating， and reusable spacecraft endure cyclic high-temperature conditions， an experimental study is conducted to investigate the effects of cyclic overheating on the tensile properties of GH3230 alloy. Additionally， the oxidation-related microstructural and compositional changes are characterized.The results reveal that the cracking of internal oxides during plastic deformation reduces the actual load-bearing area of the oxidized sample. Grain coarsening also occurs during thermal exposure. These two factors jointly contribute to a continuous decline in room-temperature tensile strength as the number of overheating cycles increases. After removing the surface layer， the tensile strength is restored to a certain degree. The oxidative decarburization zone that forms near the sample surfaces exhibits improved plastic deformability. As a result， it effectively blunts oxide cracks and prevents them from penetrating into the matrix. Consequently， the tensile elongation of the oxidized sample after 10-40 cycles of over-temperature remains at relatively high levels due to the avoidance of the notch effect caused by surface cracks.