Titanium alloys， owing to their high specific strength， excellent toughness， and outstanding corrosion resistance， are widely used in aerospace， defense， marine engineering， and medical applications. However， their high production cost remains a major barrier to large-scale adoption. This review summarizes the current research status and future development trends of low-cost titanium alloys， with a focus on both conventional design strategies and emerging technological pathways. In conventional approaches， the replacement of expensive alloying elements （e.g.， Mo，V） with more economical alternatives （e.g.， Fe， Cr， O， N）， combined with optimized melting techniques and processing routes， has significantly reduced material costs. In terms of emerging technologies， high-throughput diffusion techniques， machine learning， and transformation-induced plasticity/twinning-induced plasticity （TRIP/TWIP） mechanisms provide a crucial theoretical foundation for the rapid development of high-performance， low-cost titanium alloys that can be fabricated via short-process routes.Near-net-shape forming techniques， with their high material utilization and short processing cycles， have become key tools for cost control.Looking forward， integrating TRIP/TWIP-based alloy design with advanced processing and manufacturing techniques， along with the strategic optimization of interstitial elements （e.g.， O， N）， is expected to further reduce production costs. Such progress will accelerate the large-scale application of titanium alloys in fields such as automotive light-weighting and military armor， ultimately promoting their widespread adoption across multiple industries.

The dispersion uniformity of titanium alloy/graphene oxide （GO） mixed powder is crucial for the preparation of high-quality graphene-reinforced titanium matrix composites. The mechanism of GO adsorption onto the surface of titanium alloy particle is revealed by theoretical analysis and a quantitative evaluation method is established based on image segmentation using deep learning and statistics analysis. The results show that the SEM secondary electron images of the mixed powder dried for 12 h after solution stirring mixing exhibit high imaging contrast and strong GO adsorption state. The additional pressure generated by the pressure difference between the inside and outside of the liquid bridge is the dominant part for GO adsorption force onto the surface of titanium alloy particle，which is ten orders of magnitude higher than the force of GO. The U-Net network model demonstrates superior segmentation performance for the mixed powder and GO compared to DeepLabV3+ and PSPNet. Under the optimal training parameters，the segmentation accuracies of U-Net for the mixed powder and GO reach relatively high values of 0.9433 and 0.8774， respectively. The stirring blades shape，stirring speed， and stirring time are optimized by numerical simulation of stirring process and the established quantitative evaluation method. The paddle with three inclined blades is the preferred stirring paddle shape for preparing titanium alloy/GO mixed powder. For the mixed powder containing 0.15% （mass fraction， the same below） GO， the preferred stirring process is 400 r/min for 40 min， where the standard deviation and range of GO content are 0.82% and 2.15%， respectively. For the mixed powder containing 0.30%GO， the preferred stirring process is 300 r/min for 80 min， and the standard deviation and range of the GO content are 1.03% and 3.40%，respectively.

Continuous SiC fiber-reinforced Ti₃Al（SiC_f/Ti₃Al） composite combines the advantages of high damage tolerance and ease of forming for Ti₃Al matrix and high-strength for SiC fibers. It is an ideal candidate material for lightweight， high-strength， and high-temperature resistant fasteners in the aerospace field. However，complex residual stresses are inevitably introduced during the thread machining process of SiC_f/Ti₃Al composites. Therefore，analyzing the residual stresses in the threaded regions of SiC_f/Ti₃Al composites is of great significance for enhancing the service safety and reliability of fasteners. Given the complex geometric structures of the threaded regions in turned SiC_f/Ti₃Al composites and the close relationship between their stress distribution and core diameter， the characterization and analysis of stress are challenged by the intricate thread profile and limited dimensions. Residual stress measurements and analyses are conducted on the thread crest and radial cross-sections of the threads using side-inclined X-ray diffraction and nanoindentation method，respectively. The results show that the thread crest is in a state of compressive stress after turning. When the core diameter increases from 3.0 mm to 4.0 mm，the compressive stress increases from 387.6 MPa to 540.6 MPa. The radial cross-sections of the thread are also under compressive stress. As the core diameter increases from 3.0 mm to 4.0 mm，the compressive stress at the same location 100 μm from the thread crest increases from 326.9 MPa to 430.8 MPa. Furthermore， the compressive stress decreases with increasing distance from the thread crest.

To precisely control the thermally/stress-induced products in β-type titanium alloys and overcome the limitations of traditional design methods relying on parameters such as d-electron alloy theory and molybdenum equivalent， a design approach based on specific orientation moduli （Young’s modulus E₁₀₀， tetragonal shear modulus C′， and shear modulus G₁₁₁） is proposed. Three Ti-Mo-based multi-component alloys with significant twinning-induced plasticity（TWIP） effect， namely Ti-13.5Mo-3.6Nb（mass fraction/%， the same below）， Ti-13Mo-4.5Nb-1.6Zr， and Ti-12.5Mo-6.5Nb-1.5Zr-0.9Al， are successfully designed. By means of optical microscopy（OM）， transmission electron microscopy（TEM）， electron backscatter diffraction （EBSD）， and tensile testing， the cold workability， thermally-induced metastable phases， and stress-induced deformation modes of the designed alloys are systematically analyzed， and the regulation of specific orientation moduli on thermally/stress-induced products is investigated. The results show that all three designed alloys exhibit excellent cold workability with a cold working rate of over 90%， and the solution-treated microstructure consists of a β-phase matrix and trigonal thermally-induced ω-phase. Their yield strength ranges from 370 to 428 MPa， total elongation from 46% to 50%， and the deformation mode is dominated by ｛332｝_β〈113〉_β twinning. The high Young’s modulus E₁₀₀（22.9 GPa） of the three alloys completely suppresses the thermally/stress-induced α″-martensitic transformation； the low tetragonal shear modulus C′（7.8 GPa） facilitates ｛332｝_β〈113〉_β twinning， resulting in a twin area fraction of 28.8%-30.1% at 5% deformation； the high shear modulus G₁₁₁（10.6-10.7 GPa） inhibits the collapse process of the thermally-induced ω-phase， thereby maintaining the trigonal structure of the thermally-induced ω-phase. The design approach based on specific orientation moduli proposed in this study enables the efficient design of Ti-Mo-based multi-component TWIP titanium alloys， combining innovation and practicality. It provides a new pathway for the research and development of high-performance titanium alloys，and possesses broad engineering application prospects.

The rotorcraft structures have typical characteristics such as small batches， multi-specifications， complex shape and high-performance requirements. Additive manufacturing technologies have the ability to integrally form complex shapes and structures and produce on demand， which can achieve lightweight and rapid preparation of structures. It is an ideal process preparation solution for rotorcraft structures. However， although additive manufacturing technologies originating from rapid prototype preparation have been used in rotorcraft structures for more than 10 years， due to many challenges such as the stability of additive manufacturing technology structural parts preparation， extremely high R&D certification costs and rapid technology iteration， for rotorcraft structures， additive manufacturing technology still belongs to the category of new materials， new processes and new technologies. In order to meet the efficient application demand of additive manufacturing technology in domestic rotorcraft structures， based on the application status and development trend of additive manufacturing technology in foreign rotorcraft structures are reviewed and examined， development suggestions for the engineering application of additive manufacturing technology in domestic rotorcraft structures are proposed： constructing quantitative evaluation criteria for the application of additive technology in rotorcraft structures， establishing structural design optimization technology for additive manufacturing， developing high-performance materials， new additive manufacturing processes and high-quality post-processing methods for additively manufactured structural parts， realizing real-time monitoring and process parameter control of additive manufacturing process and universal and efficient airworthiness.

As the demand for aerospace vehicles to withstand high temperatures， ultra-high speeds， and extremely harsh service environments becomes increasingly prominent， there are higher requirements for thermal protection materials in terms of temperature resistance， durability， and reliability. Surface coating technology has become one of the effective ways to improve the oxidation and ablation resistance of composite materials in high-temperature environments. Among these， ceramic coatings， with advantages such as high melting point， high hardness， good chemical stability， and excellent oxidation and ablation resistance， have become a key research direction in the field of surface coating technology. Well-performing ceramic coatings can protect the substrate from harsh external environments such as high temperatures， oxygen-rich conditions， and strong airflow， thereby extending the service life of composites and promoting their application in fields such as aerospace and marine. Addressing the extreme service environments faced by high-Mach-number vehicles， this paper systematically reviews the research progress in high-temperature performance testing technology for ceramic coatings， based on current advancements in testing performance. It focuses on a comprehensive comparative analysis of three core evaluation technologies： static oxidation resistance， thermal shock resistance， and dynamic oxidation ablation， including their testing methods， principles， applicable ranges， and limitations. To address some of the bottlenecks faced by antioxidant ablation ceramic coatings in performance evaluation， future efforts should focus on developing multi-field coupled simulations， establishing performance prediction frameworks， and promoting standardization of testing， to overcome technical barriers and accelerate the research， development， and application of high-performance coatings.

Grain-oriented silicon steel stands as the cornerstone soft-magnetic material for ultra-high voltage transformers and high-efficiency energy-saving distribution transformers. Its outstanding magnetic properties， characterized by high magnetic flux density and low core loss， are mainly ascribed to the well - defined Goss texture in the final microstructure. Nevertheless， the mechanism governing the abnormal grain growth （AGG） of Goss grains during annealing is exceedingly intricate and remains incompletely understood， posing a significant bottleneck that impedes the further enhancement of its magnetic performance.This review comprehensively summarizes the nucleation and growth behaviors of Goss grains throughout the entire manufacturing process， spanning from hot rolling to high-temperature annealing， and delineates the optimization strategies for key production processes. It also systematically synthesizes the typical features of abnormally grown Goss grains， such as grain size， orientation deviation， and internal island grains， with a particular emphasis on analyzing how these features influence magnetic properties and the corresponding regulatory approaches. Moreover， a thorough review is conducted on various theoretical models proposed for the AGG mechanism of Goss grains， covering their fundamental principles， applicability， and limitations. Finally， key research directions for future investigations into the Goss AGG mechanism are proposed， aiming to offer a valuable reference for promoting the development of high-performance grain-oriented silicon steel.

Stainless steel is mainly used for components such as thermal molten salt tanks， heat transfer pipes， heat exchangers， valves， and pumps in solar thermal power generation systems. Molten salt， with its excellent thermophysical properties， serves as the heat transfer and storage medium in solar thermal power generation. However， molten salt exhibits strong corrosive properties towards metal materials. This paper provides an overview of the corrosion assessment and mechanisms of stainless steel in molten salt environments. Firstly， the application of stainless steel in solar thermal power generation systems and its corrosion evaluation in molten salt are introduced. Subsequently， the main corrosion types of stainless steel in molten salt， as well as the corrosion mechanisms in nitrate， carbonate， and chloride salts， are summarized. Austenitic stainless steel meets the corrosion rate requirements for structural materials in solar salt， aluminum-containing stainless steel exhibits superior corrosion resistance in carbonate salts， and 310 stainless steel is suitable for use in purified chloride salts under inert atmosphere protection. The corrosion of stainless steel in molten salt mainly depends on the types of salt anions. Corrosion in salts containing oxygen anions and halide salts is categorized under the molten salt acid-base theory， while chloride salt corrosion also involves the activation-oxidation theory. Finally， the electrochemical corrosion behaviors of atmosphere， impurities and temperature that affect the corrosiveness of molten salt are discussed， and it is pointed out that chloride salt purification can greatly reduce the corrosion of metal materials. Aluminum-containing stainless steel can form a more stable A1₂O₃ passivation film in the oxygenated anionic salt， which can effectively prevent the dissolution of chromium and iron and the penetration of corrosive impurities， which is the main research direction of molten salt corrosion-resistant stainless steel.

Hydrogen energy is known as the “ultimate energy of the 21st century”， and the production of hydrogen is also one of the focuses of attention in the 21st century. Semiconductor photocatalysts offer a promising approach to producing hydrogen under visible light. Vanadium oxide has the characteristics of multiple oxidation states， multiple coordination numbers， high stability， and a narrow band gap， so it has a wide application prospect in the field of photocatalytic hydrogen production. However， vanadium oxide has defects， including a small specific surface area， insufficient visible light absorption， and rapid photogenerated carrier recombination， resulting in low photocatalytic performance. Therefore， it is crucial to optimize the photocatalytic performance of vanadium oxide to improve the efficiency of photocatalytic hydrogen production. In this paper， the application of vanadium oxide in photocatalytic hydrogen production at home and abroad in recent years is reviewed， and the optimization strategy to improve the photocatalytic hydrogen production performance of vanadium oxide is discussed and analyzed. That is， the photocatalytic hydrogen production activity is improved by surface modification， element doping， and heterojunction construction to increase the specific surface area， enhance light absorption， and inhibit the rapid recombination of photogenerated carriers. The hydrogen production performance of vanadium-based photocatalysts prepared by different optimization strategies will be improved continuously in the future. Industrial production is expected to be achieved， which can efficiently convert solar energy into hydrogen energy and replace fossil fuels.

With the increasing emission of CO₂，the harm to the environment is gradually increasing. Reducing CO₂ emissions and reducing the concentration of CO₂ in the atmosphere is a hot topic of current research. CO₂ is not only a greenhouse gas but also a rich and cheap carbon resource. The green and efficient conversion of CO₂ into high-value-added carbon and the realization of CO₂ resource utilization can help solve environmental problems and bring economic benefits. Carbon dioxide has good chemical stability and requires a significant amount of energy to decompose. Therefore，it is extremely challenging to use CO₂ to produce high value-added carbon. However，oxychloride-containing molten salts and molten carbonates can effectively absorb CO₂ to form carbonate ions，and carbon products can be obtained by electrochemical reduction of carbonate ions. In this review，the CO₂ capture and electrochemical reduction of CO₂ by molten salt are analyzed and summarized，and the effects of molten salt electrolyte system，electrode materials，and electrolysis temperature on electrochemical reduction of CO₂ are expounded，the preparation of carbon nanotubes，carbon nanospheres，graphene，and other high value-added carbon by molten salt electrolysis is summarized and prospected.