With the improvement in aeroengine performance，critical components （such as centrifugal impellers） operate under high-temperature，high-stress，and complex load conditions. Geometric discontinuities （such as ventilation holes and fillet radii） have become weak points for fatigue failure. This study focused on TA19 material，preparing smooth and U-shaped notch specimens for low-cycle fatigue tests under high-temperature conditions. Fatigue life data have fitted using the Weibull distribution，and an improved iterative fatigue life model is proposed to address the limitations of traditional models in regions with stress concentration. The model incorporates the stress concentration factor （K_t） and first-order reliability theory for correction. The results indicate that due to stress concentration effects，U-shaped notch specimens exhibit more concentrated fatigue life distributions，whereas smooth specimens show greater variability. The Kolmogorov-Smirnov test verifies that the data conforms to the Weibull distribution characteristics. The revised model significantly improves the prediction accuracy，with most of the predicted data falling within±1.5 times the scatter band. Additionally，P-S-N curves for different failure probabilities are constructed，providing a valuable reference for the reliable fatigue life prediction of complex structures.

The Fe-Ga alloy， a novel magnetostrictive material， distinguishes itself with a low driving magnetic field and remarkable magnetostrictive performance. As an alloy， it has garnered significant attention from researchers in solid-state physics and materials science due to its cost-effectiveness， superior mechanical properties， and high stability. These advantages make it particularly appealing for applications in micro-displacement devices， vibrators， and sensor technologies. The magnetostrictive characteristics of Fe-Ga alloys are influenced by various factors， including material texture orientation， magnetic domain distribution， alloying element additions， and， most importantly， the alloy’s phase structure. This paper provides an in-depth exploration of the phase structure of Fe-Ga alloy and comprehensively summarizes the impacts of various preparation methods on enhancing the preferred grain orientation 〈100〉. It further examines the effects of specific external magnetic fields and prestresses on altering the distribution of magnetic domains， as well as the influence of incorporating rare earth elements on improving magnetostrictive performance. Additionally， the article introduces recent research advancements regarding the influence of heat treatment on phase structure transformation and nanoprecipitate phase precipitation on the magnetostrictive properties of Fe-Ga alloys，contributing to advancing the understanding， promotion， and application of Fe-Ga alloy in the field of structure-function integrated precision device manufacturing.

This study utilizes mushroom stalks as a biological template and melamine as a precursor for carbon nitride to synthesize g-C₃N₄/C，via thermal polymerization method. Copper sulfate pentahydrate （CuSO₄·5H₂O），ammonium molybdate tetrahydrate （（NH₄）₆Mo₇O₂₄·4H₂O），and thiourea （CH₄N₂S） are selected as the sources for Cu，Mo，and S，respectively. A two-step hydrothermal process is employed to prepare CuS/MoS₂ composites with different mass ratios. Then CuS/MoS₂ is anchored on the surface of g-C₃N₄/C to obtain CuS/MoS₂-g-C₃N₄/C composite electrode materials. The composite electrode materials are characterized by their phase structure，microstructure，pore structure，and capacitance performance. The results indicate that the CuS/MoS₂-g-C₃N₄/C composite electrode materials exhibit high purity，good crystallinity，good phase contact interface， and abundant porous structure. In electrochemical performance testing，the CuS/MoS₂ composite material with a mass ratio of MoS₂ to CuS at 1∶2 demonstrates optimal electrochemical performance，achieving a specific capacitance of 230 F·g^-1 at a current density of 1 A·g^-1. When the mass ratio of CuS/MoS₂ to g-C₃N₄/C is 1∶1，the CuS/MoS₂-g-C₃N₄/C composite material exhibits the best electrochemical performance，with a specific capacitance of 434.7 F·g^-1. Moreover，after 1000 cycles，the capacitance retention rate is 89.2%，showing good stability.

The MnO₂ and VB₂ co-doped NiCr₂O₄ coatings（MV） with different ratios of moles are prepared by atmospheric plasma spraying（APS）， and the phase composition， microstructure， infrared emissivity and thermal shock resistance of the coatings are investigated. The results show that the co-doping of NiCr₂O₄ with MnO₂ and VB₂ can more effectively improve the infrared emissivity of the coatings than the doping of MnO₂ or VB₂， thus the coating with MnO₂ and VB₂ doping ratio of 1∶1 （MV11） has the highest emissivity. In the 0.75-2.5 μm wavelength ranges， the room temperature band emissivity of the MV11 coating is 0.928， and in the 2.5-25 μm， the infrared emissivity of the coating increases from 0.884 at room temperature to 0.918 at 1000 ℃. It is mainly attributed to the transition metal ions and B ions enter the spinel lattice， increasing the concentration of oxygen vacancy in the lattice， introducing partial energy levels into the bandgap， and causing lattice distortions， enhancing free carrier transition absorption and infrared lattice vibration absorption. In addition， after 30 thermal cycles of water cooling at 25-750 ℃， microcracks appear in the coating， but the phase structure did not change significantly， and the emissivity decreases slightly， indicating that the coating has good thermal shock resistance.

Silicon carbide and 2024 aluminum alloy powders with average particle sizes of 14 μm and 15 μm are selected as the reinforcement phase and matrix alloy， respectively. SiC_p/2024Al composites with volume fractions of 35%， 45%， and 55% are fabricated by hot isostatic pressing. The influence of aging treatment on the mechanical properties of the composites is investigated. The results show that aging treatment significantly enhances the hardness of the composites. Increasing the aging temperature and the volume fraction of SiC both shorten the peak aging time of the composites. When the aging temperature is increased from 160 ℃ to 190 ℃， the peak aging time of the composite with a 35% volume fraction is reduced from 9.5 h to 2 h. At 190 ℃， the peak aging time of all three volume fraction composites is shortened to 2 h. The precipitation strengthening of the matrix alloy during the heat treatment process results in higher flexural strength in the aged composites compared to the as-sintered composites with the same volume fraction. The higher the matrix alloy content， the more significant the strengthening effect. Among them， the peak-aged composite with a 35% volume fraction exhibits the highest flexural strength， reaching 901 MPa at 170 ℃. With the increase of volume fraction， the matrix alloy content decreases， reducing the ability of the material to alleviate local stress concentration through plastic deformation. Moreover， defects in the composites gradually increase. Therefore， both the as-sintered and heat-treated composites with a 55% volume fraction exhibit lower flexural strength. However， the micro-yield strength of the aged composites is higher than that of the as-sintered composites. The aged composite with a 45% volume fraction generally has the highest micro-yield strength， fluctuating in the range of 361-380 MPa， while the aged composite with a 55% volume fraction has the lowest micro-yield strength. The micro-yield strength of the composite with a 35% volume fraction initially increases and then decreases with increasing temperature， reaching its highest value （368 MPa） at 180 ℃， slightly higher than that of the composite with a 45% volume fraction under the same conditions.

Carbon fiber reinforced thermoplastic composites（CFRTP） have superior comprehensive mechanical property，as well as rapid prototyping，weldability and recyclability.The application of CFRTP are gradually increasing in aerospace，vehicle manufacturing and other fields.Ultrasonic welding is recognized as one of the most suitable methods for CFRTP.With the increase of the application of CFRTP in aerospace main load-bearing structures，the discrete solder joints in the form of traditional ultrasonic spot welding are difficult to meet the requirement of the strength of them.Accordingly，foreign scholars have proposed ultrasonic continuous welding technology to realize the seam welding connection of CFRTP structures，which has not been reported in domestic literature.In this paper，the research results of CFRTP ultrasonic continuous welding are reviewed from four aspects：CFRTP ultrasonic continuous welding equipment，joint design，process characteristics and quality inspection.The scientific problems and technical bottlenecks to be solved in CFRTP ultrasonic continuous welding are discussed，so as to provide a reference for the development of CFRTP ultrasonic continuous welding technology of our country.

Microstructures and mechanical properties of GH4169 alloy cylinder and its weld joints in a supercritical water reactor are studied after operating 2000 h. The results show that the GH4169 alloy cylinder exhibits good corrosion resistance under conditions of high temperature， high pressure， and sucrose mixed solution； the thickness loss rate of the cylinder is 0.005-0.255 μm/h； the corrosion products primarily consist of oxides and phosphates. However， the welded joints connecting the cylinder and other components represent a vulnerable point that significantly impacts the remaining lifespan of the reactor. The calculated crack propagation rate of the GH4169 alloy cylinder is 5.25 μm/h， indicating that it would only take 762 h for the crack to penetrate through the wall of the connector. Additionally， severe fracture occurs （the circumferential length of the crack is approximately 1/4 of the circumference） at the weld joint between cylinder and stainless-steel， resulting from the synergistic effects of galvanic corrosion， crevice corrosion， and concentrated stress. Despite these challenges， the strength loss of the cylinder is relatively small， which means that the cylinder maintains satisfactory mechanical properties.

The β titanium alloy Ti-1300 is fabricated utilizing laser engineered net shaping （LENS） technology. This study systematically examine the microstructural evolution of the alloy along the deposition direction during the LENS process， and elucidate the intrinsic relationship between its mechanical properties and microstructure. The results indicate that the thermal cycling of each deposited layer in the LENS process has a profound impact on the microstructural evolution. Initially， columnar crystals are formed with a thickness of （15.6±1.2） mm， comprising approximately 20% of the total deposited thickness. Subsequently， these grains transform into equiaxed grains. Within the as-deposited grains， the microstructure undergo a transition from a basket-weave structure to a lamellar structure， and the discontinuous grain boundary α phase changes to a continuous grain boundary α phase along the deposition direction. Notably， the basket-weave microstructure imparts exceptional strength to the alloy. However， the continuous grain boundary α phase tends to promote intergranular fracture， resulting in reduced ductility.

To address the evolving demands for the clean and efficient utilization of coal， efforts have been devoted to the research and development of C700R-1 nickel-based alloy rotor forgings for advanced ultra-supercritical steam turbine rotors. Concurrently， tests are conducted on the conventional mechanical properties and creep rupture properties of the trial-manufactured rotor forgings. The results show that the use of the closed upsetting+extrusion method enables the high-homogeneity forging of Φ850 mm forgings. The as-forged grain size of the developed large-section forgings ranges from grade 4 to grade 7， and the grain size after heat treatment is approximately grade 3. Due to the rapid cooling rate of the edge parts after solid solution， a large number of uniform and fine γ' phases precipitate in the subsequent aging process. Therefore， the tensile properties of edge position are slightly better than those of the heart and 1/2R position. The variation of tensile properties in different directions of edge position is small. The room temperature tensile strength can reach 950 MPa， the yield strength can reach 600 MPa， and the V-notch absorbed energy at room temperature is beyond 70 J at different positions after heat treatment. The tensile strength can reach 750 MPa， yield strength can reach 500 MPa at 700 ℃. The plasticity is higher than 25% at room temperature and 700 ℃. The creep life exceeds 7000 h in the condition of 700 ℃/300 MPa. Through the deformation mode of closed upsetting+extrusion and reasonable heat treatment process， the homogenization manufacturing of nickel base alloy forgings with a section grade of Φ850 mm， which provides key data for the subsequent manufacturing of full-size nickel base alloy rotor forgings.

The desirable combination of ultra-high strength and good toughness enables the secondary hardening ultra-high strength steel widely used in aerospace and energy equipment. The influence mechanism of quenching temperatures on the microstructure and mechanical properties of Co-conserving 2.2 GPa ultra-high strength steel is investigated by using scanning electron microscope（SEM），transmission electron microscope（TEM），tensile and impact testing machine. The results show that when the quenching temperature is 950 ℃， there are many undissolved M₆C carbides and unrefined grains in the matrix， resulting in lower strength （tensile strength：2072 MPa， yield strength：1873 MPa）. As the quenching temperature increases， recrystallization promotes the refinement of the matrix grains， and the number of M₆C carbides gradually decreases； such partial dissolution favors the precipitation of hardening phases， resulting in a recovery of strength； when the quenching temperature is 1030 ℃， the experimental steel has excellent combination of strength-plasticity-toughness： the tensile strength is 2251 MPa， the yield strength is 1901 MPa， the elongation is 9%，and the V-notch impact absorbed energy is 9 J. By further increasing the quenching temperature， the rapid growth of austenite grains leads to severe plasticity attenuation， with elongation of only 4.5% at 1120 ℃. Between 1030-1090 ℃， there is a competitive relationship between the dissolution of M₆C carbides and grain growth. Although higher temperature quenching promotes dissolution， the severe coarsening of grains offsets the former’s beneficial effect on toughness to enable a stable performance of strength and toughness.