This paper reviews the epoch-making significance of advanced materials in the history of human civilization, emphasizes that materials fall within the scope of applied science and the purpose of materials research lies in application. The “two whole processes” endow materials with ultimate intrinsic properties and ultimate service performance, thus forming the discipline of “Materials Science and Engineering”. This is the only way to build a leading country in materials. Five commanding heights for such a country are proposed, namely commanding heights in theory, technology, performance, industry, and system.

Performance enhancement of advanced aero-engines sets a higher requirement for their overall structural lightweighting. Polymer-matrix composite (PMC) are one of the key materials to achieve aeroengine lightweighting. In recent years, focusing on the aero-engine cold-section parts, AECC Beijing Institute of Aeronautical Materials (BIAM) has systematically developed PMCs of high-toughness epoxy, high-temperature and high-toughness bismaleimide, high-temperature polyimide and high-toughness thermoplastic resins. This article introduces the foreign profile of PMCs for aero-engines and the demands of aeroengines for PMCs. Then, taking BIAM as the representative, domestic current status of PMCs for aero-engines and application are introduced. PMC development trend and emphasis for aero-engines are proposed. Overall, domestic PMC for aero-engines have made breakthrough in such aspects as high-temperature resistance, impact resistance, structure/function integration and integral fabrication technology, and have achieved batch application in such parts as fan blades, containment casings and outer ducts. For the needs of future aero-engines, PMC would focus more and more on the directions including thermal resistance enhancement, toughness improvement, structure integration, processing automation and intelligentization, full-life cost minimization.

Single crystal superalloys exhibit excellent comprehensive properties and have been widely applied in advanced aero-engines. This paper reviews the development of single crystal superalloys from the aspects of strengthening mechanism and composition design, directional solidification and crystal growth, solid-state phase transformation and heat treatment and mechanical behaviour. Special emphasis is placed on the research progress of the high-performance, low-cost single crystal superalloys with independent intellectual property rights of China developed by Beijing Institute of Aeronautical Materials, and future development direction of single crystal superalloys are discussed.

The design life of turbine blades in heavy-duty gas turbines (HDGT) typically reaches tens of thousands of hours, operating under conditions characterized by high stress, prolonged thermal exposure and coupled hot corrosion induced by complex media such as high salt and high sulfur. This paper systematically reviews the current research status and development trends of directionally solidified columnar (DS) and single crystal (SC) nickel-based superalloys for HDGT applications. Firstly, the graded material allocation strategy of “high performance for high-temperature front stages and cost-effectiveness for low-temperature rear stages” is clarified, noting that the core design logic has shifted from seeking instantaneous ultimate strength to ensuring long-term microstructural stability. Secondly, the evolution of alloy compositional design is emphasized, analyzing the “low-Re design philosophy” characterized by reduced Re content, optimized W/Mo ratios and increased Cr levels to suppress the precipitation of topologically close-packed (TCP) phases and enhance environmental resistance. Furthermore, considering the massive scale of HDGT blades, the challenges in manufacturing large-scale components are discussed, specifically the thermal-solute-stress multi-field synergistic instability induced by scale effects and the “microstructure inheritance effect” of dendritic segregation on service performance. Finally, this review elucidates the multi-mechanism coupled evolution of creep, fatigue and environmental damage under long-term service conditions, and highlights the prospective engineering applications of repair and life-extension technologies in life-cycle management. It emphasizes that the core of future development lies in reconstructing the surface protection systems of large-scale blades and efficiently restoring the degraded internal microstructures, without compromising the structural integrity of the original single crystal or directionally solidified substrates. It is pointed out that breaking through the bottleneck of casting yield for large-scale complex blades and improving hot corrosion resistance under extreme environments are the core challenges currently faced. Future research should focus on the synergistic optimization of mechanical-environmental performance and physics-based life prediction models to support the development of next-generation high-parameter gas turbines.

As an emerging moulding technology, 3D printing has steadily matured and is poised to supplant the traditional hot-press injection moulding technology, emerging as a pivotal approach for manufacturing ceramic cores in aerospace turbine blades. Nevertheless, 3D-printed ceramic cores produced through 3D printing display significant anisotropy in mechanical properties, including sintering shrinkage rate and strength, owing to their layered structure and directionally arranged porosity. This anisotropic characteristic severely impedes their manufacturing potential and application scope, posing a critical challenge that demands urgent resolution. This paper offers a systematic summary of the manifestations of anisotropy in 3D-printed ceramic cores, clarifies the underlying formation mechanisms, formulates evaluation criteria, and puts forward effective control strategies. Additionally, it delineates future research directions, encompassing material system innovation, process optimization, comprehensive property regulation, multi-technology integration, and intelligent manufacturing methods. These endeavors lay a solid theoretical groundwork for promoting the high-performance realization and large-scale application of 3D-printed ceramic cores.

This paper reviews the research work carried out by the research group on wrought superalloys and their preparation processes over the past more than ten years. On one hand, regarding wrought superalloys for aerospace applications, including high-strength hard-to-deform superalloys serving above 750 ℃, a new generation of low-expansion superalloys with both structural and functional properties, and wrought superalloys for high-strength fasteners at elevated temperatures, the microstructural characteristics and typical properties of these new materials are elaborated. On the other hand, in terms of wrought superalloys for nuclear reactors, the research progress and microstructural and performance characteristics of corrosion-resistant and irradiation-resistant high-temperature nuclear structural materials are introduced. Meanwhile, the research progress of advanced technologies such as the hot extrusion cogging process for fine-grained and homogeneous wrought superalloy bars and the hot extrusion forming process for hollow thin-walled long shaft forgings is presented. Finally, the research and development of wrought superalloys, process technology advancement, and industrial prospects in China are prospected: (1) establish an independent forward research and development system; (2) break through the full-process stable preparation technology; (3) expand cross-domain applications; (4) promote the large-scale recycling of returned materials.

Powder metallurgy superalloys have become the preferred material for turbine disks of advanced aero-engines due to their advantages such as segregation-free microstructure, uniform microstructure distribution, and excellent comprehensive properties. However, their highly alloyed composition and complex manufacturing processes make the traditional trial-and-error research mode confronted with multiple challenges, including long development cycles, high research costs, and unclear research orientation. Digital technologies have emerged as a critical approach to breaking through the above bottlenecks. This paper summarizes the applications of the full-scale digital technology system covering electron, atomic, mesoscopic, and macroscopic scales in the research of powder metallurgy superalloys, and prospects its future development trends. At the electronic scale, first-principles calculations and related methods are mainly adopted to screen alloying elements, clarify the mechanism of phase stability, and calculate the interfacial energy of γ/γ′ two-phase structures. At the atomic scale, molecular dynamics simulations are used to reveal the influence of inclusions on crack initiation and propagation, as well as the interaction mechanisms of dislocations, twins, grain boundaries, and other microstructural features during deformation. Mesoscopic scale methods, such as crystal plasticity, phase field, and cellular automaton, are applied to simulate the evolution of particle sintering, two-phase microstructure and grain structure, and their effects on mechanical properties. Macroscopic scale methods focus on simulating the evolution of macroscopic stress field, temperature field and average mesoscopic microstructure field in manufacturing procedures including powder preparation, hot isostatic pressing and heat treatment. Artificial intelligence and digital twin technology are revolutionizing the research and development of powder metallurgy superalloys. Based on massive experimental data, artificial intelligence adopts various algorithms represented by machine learning to provide definite guidance and schemes for composition optimization and process improvement. Digital twin establishes virtual mapping of physical components, aiming to realize accurate full-process simulation, real-time condition diagnosis, and life prediction throughout manufacturing and service stages. Finally, this study points out that future digital technologies need to develop toward the integrated prediction and optimization of cross-scale and cross-process preparation-service performance, so as to support the upgrading and innovation of aero-engine turbine disks with short development cycles, low costs, high reliability, and long service life.

Technological innovation in high-performance damage-tolerant titanium alloys for aerospace equipment stands as a core strategic pillar, enabling China’s aviation industry to achieve independent design of equipment structures, localization of key technologies, and leapfrog industrial development. This paper conducts a comprehensive review of the research status and technological advancements in damage-tolerant titanium alloys for aeronautical structures both domestically and internationally, and focuses on expounding the research breakthroughs and engineering application achievements of new high-performance damage-tolerant titanium alloys for aircraft structures by Beijing Institute of Aeronautical Materials. The study proposes that adhering to the core of “demand-driven, systematic development, and cross-generation research and development” is the fundamental path to promote the iteration of China’s new-generation aeronautical high-performance titanium alloy material technologies. To this end, by making breakthroughs in key technologies such as precise alloy composition design, high-purity and clean smelting, homogenization forming of large-sized bars, integrated processing of integral forgings, and multi-scale comprehensive strengthening and toughening, a backbone material system of titanium alloys for Chinese aircraft structures with independent intellectual property rights has been initially established, covering three series of damage-tolerant titanium alloys: medium-high strength and high toughness, high strength and high toughness, and ultra-high strength and high toughness. Meanwhile, to meet the dual requirements of lightweight and cost-effective aeronautical structures, a new type of medium-high strength and high toughness, low-cost damage-tolerant titanium alloy and its application technology have been successfully developed. This development achieves the collaborative optimization of strength and toughness and the optimal performance matching of three typical microstructures of the alloy, providing a new approach for the lightweight design and engineering application of aeronautical structures. Future research should further integrate cutting-edge technologies such as artificial intelligence-assisted material design and additive manufacturing, strengthen basic theoretical research and engineering verification, and lay a solid theoretical foundation and provide technical support for the further enhancement of performance and wide-scale engineering application of high-performance damage-tolerant titanium alloy materials in China.

Due to the sensitivity and complexity of the composition-process-microstructure-performance relationship, the research and development of high-performance titanium-based materials have long been constrained by the dual challenges of high-dimensional nonlinear optimization and high trial-and-error costs. As a highly pervasive disruptive technology, artificial intelligence (AI) is introducing a new research and development paradigm for the strategic field of high-performance titanium-based materials, shifting from experience-driven modes to dual-driven approaches supported by models and data. This review summarizes the latest research advances in artificial intelligence-enabled high-performance titanium-based material technology (AI+Ti), focusing on how AI provides innovative solutions targeting the inherent characteristics of high-performance titanium-based materials, including complex compositions, diverse phase transitions, narrow thermal processing windows, and strong path dependence of microstructure evolution. The main contents include breakthroughs achieved by AI in constructing high-precision phase diagram and performance prediction models, as well as realizing the inverse design from performance objectives to microstructures and further to composition and processing parameters; the intelligent upgrading from forming control to active regulation of microstructures and properties in key processes such as additive manufacturing and heat treatment; and the establishment of an in-service behavior prediction framework based on digital twins. On this basis, this paper further analyzes the core challenges in the AI+Ti field regarding data, models, verification and integration, and prospects future development directions such as physics-informed machine learning and autonomous experimental platforms. Finally, it discusses controversial issues involving knowledge representation, human-machine collaboration modes and engineering trust establishment, and elaborates on the future development trends of this field: (1) material performance prediction and multi-scale coupling under complex service environments; (2) intelligent coordination of full-process processing parameters; (3) the construction and iteration of specialized physics-informed perception models for titanium alloys. Beyond simple tool application, AI+Ti has evolved into a transformative revolution that enables in-depth understanding and ultimate mastery of the cognition and research paradigm for high-performance titanium-based materials.

TiAl alloys have advantages such as low density and excellent high-temperature mechanical properties. They can replace nickel-based superalloys in the application of aircraft rotor blades. On one hand, they can reduce the mass of the blades. On the other hand, they can reduce the centrifugal force generated by the rotation of the blades, realize the optimized design of the disk and shaft, and contribute to the weight reduction of the aero-engine structure. So far, the development of TiAl alloys has gone through three generations. The first-generation TiAl alloys have not been applied. The second-generation TiAl alloys (4822 and 45XD alloys) developed by the United States have been used in engineering. Various low-pressure turbine blades of aero-engine have been prepared by casting process, and the long-term service temperature of the blades is 650 ℃. At present, a variety of the third-generation TiAl alloys, including TNM, TNB, G8, etc., have been developed. These alloys have good comprehensive mechanical properties at 750 ℃. The third-generation TiAl alloys have not been used in engineering in the field of aero-engine. This paper reviews the development process of TiAl alloys for aero-engine, briefly summarizes the types of solid solution strengthening and precipitation strengthening elements in forged TiAl alloys, reviews the research process and current situation of the microstructure and properties, remelting process, hot working process and application of wrought TiAl alloys, analyzes the characteristics of three-phase and two-phase wrought TiAl alloys and elaborates the evolution of the microstructure and properties of two third-generation wrought TiAl alloys after long-term high-temperature exposure, providing a reference for the material selection of the third-generation wrought TiAl alloys by aero-engine designers.

As a new type of high-temperature lightweight structural material, Ti₂AlNb alloy is regarded as one of the most promising candidates to replace nickel-based superalloys for significant weight reduction in critical high-temperature components of aero-engines. At present, the development of Ti₂AlNb alloy has reached a mature stage, and its application in aero-engines is accelerating. Therefore, the demand for transitioning the properties of the material from laboratory scale to actual structural service performance is becoming increasingly urgent. This paper systematically reviews the research status and development of the application performance of Ti₂AlNb alloy in aero-engines. Based on a summary of the development progress of the alloy, material selection analysis, and current application status in engines, the application pathway of “static components first, then rotating components” and its typical potential application objects are identified. Furthermore, the requirements and key research tasks for evaluating the structural application performance of Ti₂AlNb alloys are systematically outlined from the perspectives of engine structural integrity requirements, needs for strength and life analysis methods and tools, and the establishment of a comprehensive material application evaluation system. Subsequently, taking the combustor casing structure as an example, the current research status of the structural application performance evaluation of Ti₂AlNb alloys in aero-engines is elaborated in detail. Finally, based on the current research progress, future directions for advancing the material selection and structural application performance evaluation of Ti₂AlNb alloys are proposed: future efforts should focus on real engine service conditions, systematically conduct performance evaluations under multi-factor coupled environments, establish quantitative microstructure-property correlation models and develop material-structure-performance integrated design methods, so as to provide solid support for the engineering application of Ti₂AlNb alloys in critical components such as combustor casings.

Aviation cockpit transparency is the key structural-functional component of aircrafts, and its manufacturing technology represents a cutting-edge interdisciplinary field. Regarding the current research status in this field, this paper systematically reviews the development history and current technical state of advanced aviation transparent materials and transparency technology. The paper provides a detailed summary of research achievements in aviation transparent materials, molding technologies for single-layer and multilayer composite transparencies, functional film systems for transparency and electrochromic technology. Finally, this paper provides an outlook on the development trends of advanced aviation transparent materials and transparency.

Soft magnetic alloys exhibit significant potential for applications in electromagnetic wave absorption in the gigahertz frequency band, owing to their advantages such as high saturation magnetization, excellent permeability, diverse microwave attenuation mechanisms, and flexibly tunable electromagnetic parameters. This paper provides a review of the research progress on soft magnetic alloys and their composites in the field of microwave absorption over the past five years. The methods for modulating the performance of soft magnetic alloy-based microwave absorbers are summarized, primarily including composition optimization, elemental doping and post-treatment processing, and the effects of these methods on electromagnetic parameters and microwave absorption performance are analyzed. Subsequently, the synergistic effects of incorporating hard magnetic materials, dielectric materials and insulating materials with soft magnetic alloys on enhancing microwave absorption performance are mainly discussed. Then, the auxiliary role of machine learning in the development of soft magnetic microwave absorbing materials is introduced. In summary, the development of soft magnetic alloys and their composites exhibits a clear trend toward diversification in material systems, preparation methods and morphological design. Looking forward, the deep integration of material experimentation, performance simulation and machine learning is expected to significantly accelerate the efficient development of microwave-absorbing materials in this field.

The iterative upgrading of advanced aero-engine technology has put forward higher requirements for the performance of thermal barrier coatings (TBCs). The traditional yttria-stabilized zirconia (YSZ) TBCs system can no longer meet the high-temperature and complex environmental service requirements of turbine blades. Rare earth zirconate materials have become the most promising candidate system for the next-generation TBCs of turbine blades due to their outstanding advantages such as excellent high-temperature phase stability, low thermal conductivity and good corrosion resistance. This paper systematically summarizes the research progress of rare earth zirconate TBCs prepared by electron beam physical vapor deposition (EB-PVD), comprehensively reviews their preparation characteristics, core properties and failure mechanism. It focuses on elaborating the key performance characteristics of rare earth zirconate materials, including phase structure, thermal conductivity, thermal expansion coefficient and resistance to calcium-magnesium-aluminosilicate (CMAS) corrosion, and deeply analyzes the characteristics of their multi-inducer coupled failure behavior. Finally, the technical development paths for segregation control of rare earth zirconate coatings, and the design of ultra-low thermal conductivity and high thermal expansion coatings are clarified, and the future research directions of their specific CMAS corrosion mechanism and multi-factor related failure behavior model are prospected.

Fatigue failure of critical components in aero-engines will compromise the flight safety of aircraft once it occurs. Fatigue failure mainly initiates from defects formed by metallurgical, processing, and environmental factors in the surface and subsurface layers of components, and then propagates under accumulated service damage, resulting in sudden fracture without obvious macroscopic plastic deformation, which may lead to severe risks. Surface mechanical treatment employs surface work hardening to introduce a micro-deformed layer on metallic components. Without impairing the bulk properties of the metal, it significantly improves the durability performance of metallic structures, such as fatigue resistance and stress corrosion cracking resistance, making it particularly suitable for long-life service of aero-engine components under high-performance operating conditions. In response to the development requirements of advanced aero-engines, this paper compares the state-of-the-art of typical surface mechanical treatments worldwide, puts forward development suggestions including enhanced structural adaptability, medium optimization, intellectualization, and integration into strength design, and proposes supporting strategies to ensure the rapid development and effective application of surface mechanical treatment. It provides decision-making references and technical support for the development of new-generation aero-engines and surface mechanical treatments.

Additive manufacturing is a near-net shaping technology that builds three-dimensional solid parts by depositing material layer by layer. It offers unique advantages in producing metal parts with complex structures. As a result, it has been widely used in key fields such as aerospace, biomedical and high-end mold manufacturing. However, the unique forming process of additive manufacturing introduces defect characteristics that differ from those in traditional manufacturing methods. These issues severely affect the service reliability of the formed parts and have become a critical challenge for the technology. This paper systematically summarizes the research findings of AECC Additive Manufacturing Technology Innovation Center on defects in additively manufactured metal materials. It focuses on the morphological features, formation mechanisms and effects on mechanical properties of typical defects such as holes, lack of fusion, inclusions and cracks. The paper also analyzes the role of hot isostatic pressing in closing defects and improving mechanical properties. To address current research gaps, it suggests further studies in several areas. These include revealing the relationship between defect formation mechanisms and process parameters, developing metal materials specifically for additive manufacturing, establishing defect acceptance standards based on part service requirements, and advancing intelligent online monitoring and closed-loop control technologies. These efforts aim to promote further progress of additive manufacturing.

Brazing technology is one of the indispensable key joining technologies in the manufacturing of aerospace structures, and it is widely applied to the joining of components operating under high-temperature, high-stress, and complex service conditions. This paper systematically reviews the research progress and application status of key brazing technologies for aerospace structures, with a focus on the brazing research developments of complex components such as aero-engine turbine blades, aircraft metal honeycomb sealing structures, and heat exchangers. Meanwhile, for advanced aerospace structural materials including ceramic matrix composites, TiAl high-temperature alloys, and Nb-Si refractory alloys, this paper comprehensively analyzes their current weldability research status and major technical bottlenecks in the brazing process. Finally, it is pointed out that the integration of numerical simulation and machine learning technologies, combined with multi-principal alloy design and micro-alloying regulation strategies, can significantly improve the efficiency of composition screening and process optimization for high-performance specialized brazing materials. This approach will accelerate the establishment of a comprehensive technical standard system covering the entire temperature range and manufacturing process, and further advance the theoretical research on dissimilar material joining, thereby providing robust technical support for advanced aerospace manufacturing.

As high bypass ratio turbofan aero-engines develop towards longer service life and higher reliability, the mechanical property testing and characterization of materials have become the key to ensuring their long-term reliable operation. This paper systematically reviews the progress in the testing technologies, damage characterization and service life prediction of aeroengine materials for long-life design, mainly focusing on three typical scenarios: very-high cycle fatigue of rotor blade materials, long-term high-temperature creep of turbine hot-end components and fatigue crack characterization of real process defect-limited-life materials. It introduces the application of technologies such as very-high-frequency vibration fatigue based on electromagnetic vibration tables, creep measurement based on DIC methods, creep life prediction based on segmented models/physical mechanisms and in-situ fatigue based on SEM/CT in this field. In the future, it is necessary to further study the physical mechanisms of very-high cycle fatigue crack initiation, long-life creep rate stress dependence and microstructure evolution and real process defect damage evolution of aeroengine materials. Meanwhile, it is necessary to further promote intelligent life prediction models based on transfer learning, reinforcement learning, attention mechanisms and so on to achieve an integrated evaluation of the microstructure-performance-life of aero-engine components, in order to meet the continuous challenges brought by future aero-engines.