Near-α high-temperature titanium alloys typically exhibit poor tensile strengths, falling below 1200 MPa at room temperature and 750 MPa at 600 ℃. On the basis of the cluster formula α-{[Al-Ti₁₂]（AlTi₂）}₁₂+β-{[Al-Ti₁₄]（Mo_0.08Si_0.4Nb_0.1Ta_0.32W_0.14Sn_0.96Zr₁）}₅ of Ti65 alloy, this work partly replaces the elements in the β-Ti structures unit and adds Zr instead of Ti to enhance high-temperature stability of β phase. Consequently, the composition formulas of α-{[Al-Ti₁₂]（AlTi₂）}_x+β-{[Al-Ti₁₃Zr₁]（Mo_0.125Si_0.5Nb_0.125Ta_0.5W_0.25Sn_0.5Zr₁）}_（17–x）（x=11, 12, 13 and 14）series alloys are designed by changing the ratio of α and β cluster unit. The as-cast structure of series alloys is in the form of a basket-weave composed of α plates and residual β phase. As the number of β clusters increases, α plates become increasingly finer, and the tensile strength gradually increases. Among them, the room-temperature tensile strength of Ti-5.3Al-2.5Sn-7.6Zr-0.5Mo-0.5Nb-3.8Ta-0.6Si-1.9W（x=11）reaches 1334 MPa, 28% and 21% more than the reported forged IMI834 and as-cast Ti65 alloys. However, the elongation of this alloy is only 1.3%, which is lower than that of forged IMI834 and as-cast Ti65 alloys. The tensile strength is 856 MPa at 600 ℃, 26% and 37% more than forged IMI834 and as-cast Ti65 alloys with the identical elongation.

ZTA15 titanium alloy ingots, containing oxygen levels of 0.08%, 0.12%, 0.16%, and 0.2%（mass fraction）, are produced through the levitation melting technique. The effect of oxygen content on the microstructure and mechanical properties of the alloy is examined using optical microscopy (OM), scanning electron microscopy (SEM), and X-ray diffraction (XRD). The results show that all four ZTA15 structures, varying in oxygen content, are typical Weisberg morphologies. As oxygen content increase, the α-phase bunches shorten and their orientation become more disordered. Furthermore, the widths of the α-slats in the four alloys decrease progressively, measuring 3.92, 3.06, 2.49 μm, and 2.77 μm, respectively. Initially, as oxygen content rose, both tensile and yield strengths of the alloy increase, followed by a decrease, with a concurrent decline in plasticity. Notably, the alloy with 0.16% oxygen demonstrate peak yield and tensile strengths of 1037 MPa and 909 MPa, respectively. However, when oxygen content reach 0.2%, a significant strength reduction is observed, primarily due to the formation of a coarse α-phase structure, resulting in the lowest elongation among the alloys.

Titanium matrix composites（TMCs）, as a new generation of lightweight and high-performance metals are considered to be one of the most promising structural materials in the fields of aerospace, automotive and other high-tech industries. Compared with conventional micron-reinforced TMCs, nano-reinforced TMCs（NRTMCs）exhibit more significant advantages such as the desirable strength and ductility synergies and thermal deformation capacity. However, the performance potential of NRTMCs has not been sufficiently developed due to the problems of dispersion and thermal stability of the nano-reinforcements. How to introduce nano-reinforcements and maintain their stability during thermal mechanical processing has been a serious challenge for NRTMCs. This paper reviews the research progress of the process features, fabrication methods, microstructure characteristics and mechanical properties, analyses and identifies a series of fundamental issues such as dispersion and heat stability of nano-reinforced material that constrain its development, and proposes the directions for future research. The development directions of future research focus on:（1）interface reaction control and thermal stability design; （2）batch production and low-cost preparation technology; （3）research on special thermal deformation and heat treatment process; （4）tissue configuration design and toughness mechanism and （5）other key mechanical properties research of nano-particulate reinforced TMCs.

A titanium alloy collision friction ignition device was used to conduct collision and continuous friction between TC4 titanium alloy rotating rod and TA7 and other titanium alloy collision samples.Combined with SEM and other microscopic analysis, the anti-ignition performance and products of TA7 and TC11 titanium alloys were studied, and the experimental results under this special friction condition were obtained. The research results show that the friction contact pressure P_f and the combustion chamber pressure P can be effective test parameters to evaluate the titanium alloy impact ignition process. The critical ignition curves of the three titanium alloys drawn based on P_f-P are all linear laws, and the anti-ignition performance is: TC11 > TA11 > TA7. Microscopic analysis of the titanium alloy after impact ignition shows that the combustion reaction zone of the titanium alloy consists of four regions: the combustion product zone （CPZ）, the oxide zone （OZ）, the heat-affected zone （HAZ）, and the friction product zone （FPZ） in total. The multi-layer structure of Al₂O₃ formed by TC11 after ignition is conducive to blocking the mutual diffusion of Ti, O and other elements, which is the main reason for its superior anti-impact ignition performance.

With the rapid development of low-temperature fields such as deep space exploration, polar scientific research, low-temperature storage and transportation, the service conditions for low-temperature structural components are becoming increasingly stringent. Therefore, low-temperature materials have gradually become a research hotspot in the world. This article mainly summarizes the low-temperature performance and related mechanisms of common structural materials such as low-temperature steel, aluminum alloy, titanium alloy, aluminum matrix composites and resin matrix composites. The effects of different crystal structures, alloy types, alloying elements and other factors on the mechanical properties of structural materials such as low temperature strength, plasticity and toughness, and the mechanism of low temperature deformation, strengthening and toughening are concluded. The application and prospect of different grades of low-temperature structural materials in different fields at home and abroad are also briefly introduced. The future research prospect of low-temperature materials is put forward.

With the improvement of thrust-to-weight ratio and other properties of future aero-engine, the high temperature mechanical property and structural stability of titanium alloy components are required. The limitation of traditional experiments in time and space scale has become increasingly prominent, and it is difficult to deeply study the microscopic transient phenomena and mechanisms. Moreover, the molecular dynamics（MD）calculation method takes the atomic/molecular model as the calculation object, on the basis of Newton classical mechanics and empirical parameters, the calculation efficiency is greatly improved compared with the quantum calculation method. Therefore, MD has become an important method to optimize the process parameters and calculate the microstructure properties of aero-engine titanium alloy. Based on an overview of the basic principle of MD computing space and time scale advantages, this paper reviews the relevant domestic and foreign achievements in the study of molding, microstructure characterization and performance testing of aero-engine titanium alloys by MD method in recent years, as well as representative conclusions that contribute to the improvement of high temperature resistance of aero-engine titanium alloys. Finally, the future prospect is discussed based on the demand for MD computing technology for aircraft engine titanium alloys, thus pointing out the challenges faced on the following aspects, including high-throughput composition design based on MD computing method, training molecular force fields for mature titanium alloy systems, and introducing the new ReaxFF（Reactive Force Field）into the study of combustion mechanisms.

The precipitation behavior of secondary α phase and mechanical properties of high strength TB9 titanium alloy were investigated during single aging and duplex aging. The alloy phase constitution was analyzed by XRD, and the microstructure was observed by optical microscopy and scanning electron microscopy. The evolution characteristics of the microstructure with aging temperature were mainly analyzed. The room temperature tensile properties and fracture toughness were tested. The research results indicate that during single aging, secondary α phase exhibits serrated and layered precipitation. With increasing aging temperature, the size of α phase increases, and the content of layered α phase increases. The strength at 430 ℃ aging is lower and the plasticity is higher. The strength at 470 ℃ aging is the highest. With increasing aging temperature, the strength first increases and then maintains at the similar level. During duplex aging, most of secondary α phases precipitate in a serrated shape within the grains. With increasing aging temperature, the size of α phase increases, the tensile strength first increases and then decreases, reaching a maximum of 1542 MPa. The tensile strength of duplex aging is significantly higher than that of single aging, which is mainly due to the combined strengthening effect of second phases near grain boundaries and intragranular α phases with serrated shape.

Flaw tolerance performance of TC4 alloy was investigated for helicopter transmission systems design. The impact pit flaws and scratch flaws were investigated by fatigue specimens with same flaw depth for flaw tolerance design, and high-cycle fatigue S-N curve tests were conducted. The results show that both scratch flaws and impact pit flaws significantly reduce the fatigue limit of the TC4 titanium alloy. The scratch flaw has a higher flaw influence factor（K_flaw） of 2.29 compared to the impact pit flaw’s K_flaw value of 1.75 under the same flaw depth conditions. Fracture surface analysis provided laws of the fatigue crack initiation and propagation associated with these flaws. Scratch flaws mainly exhibit multiple sources, with crack initiated at the root of the scratch, while the characteristics of fatigue crack initiation for impact pit flaws vary with the applied stress. Multiple sources are observed under high stress lever, with crack initiated on the surface of the pit, while under low stress, the crack initiates at a subsurface of the pit.

High strength Ti-5Al-3Mo-3V-2Zr-2Cr-1Nb-1Fe（Ti-5321） alloy is a new type of high strength tolerance titanium alloy designed and developed to meet the demand of high performance titanium alloy for new generation aircraft in China. Ti-5321 alloy with equiaxed microstructure（EM）, basket-weave microstructure（BW） and fine basket-weave microstructure（F-BW）was obtained by forging and heat treatment, and the tensile properties and fatigue crack growth behavior were studied. Fatigue crack propagation mechanisms in Paris and unstable propagation regimes were revealed by analyzing the microstructures and fracture morphology using optical microscopy (OM) and scanning electron microscopy (SEM). The results show that the samples with EM, BW and F-BW exhibit the excellent fatigue crack propagation resistance with the tensile strength of 1200 MPa. The sample with F-BW presents the highest fatigue crack propagation resistance in Paris and rapid growth regimes, while the sample with EM presents the lowest fatigue crack propagation resistance. In F-BW, the crack mainly propagates through and along α phase. Crack tends to propagate across colony oriented for （$ \bar{1} 011$）<$ {1}2\bar10 $> pyramidal slip and propagates along colony oriented for （$10 \bar{1} 0$）<$1 \bar{2} 10$> prismatic planes.

Key components used in the high-pressure compressor of advanced aero engines operating in the 550-600 ℃ range have an urgent demand for 600 ℃ high-temperature titanium alloy. However, the use of casting, forging, and other traditional processing techniques is not sufficient to meet the requirements for gradient or composite structures, functional integration components and complex components that are difficult to form. Additive manufacturing is an advanced manufacturing technology that offers unique advantages such as material design-manufacturing integration and complex design-customization integration. It provides a new approach to the development of new materials and technologies of 600 ℃ high-temperature titanium alloy. Currently, attention is being paid to the processing of 600 ℃ high-temperature titanium alloy by using additive manufacturing techniques at home and abroad, focusing on the relationship among materials, processing, structures, and properties. Firstly, this paper reviews the research on 600 ℃ high-temperature titanium alloy in brief, introduces the microstructure characteristics of deposited and post-treated states of 600 ℃ high-temperature titanium alloy under different additive manufacturing processes, and analyzes key properties such as tensile properties, creep properties, thermal fatigue properties, and antioxidant properties. Then, the research progress of composite materials based on 600 ℃ high-temperature titanium alloy and gradient structure built by additive manufacturing is discussed. Finally, the prospects are provided for research directions including the development of 600 ℃ high-temperature titanium alloy materials for additive manufacturing, exploration of hybrid manufacturing processes, defect control, and establishment of performance evaluation standards.

Continuous SiC fiber reinforced titanium matrix（SiC_f/Ti）composite exhibiting high specific strength, high specific modulus and high temperature resistance, shows important application prospects in the aerospace field. In this paper, the development of SiC_f/Ti composite's application, preparation, property control and testing technology is summarized, and the bottleneck problems required to be broken through are raised. SiC_f/Ti composite shows the unidirectional performance advantages, making it suitable for rotating ring parts（bling, turbine disk, etc）, rod parts（turboshaft, connecting rod, fastener, etc）and plate parts（aircraft skin, etc）. The commonly used preparation methods of SiC_f/Ti composite materials are foil-fiber-foil（FFF）method and matrix coating technology（MCT）. FFF is suitable for preparing plate structural parts, and MCT is suitable for winding structural parts, such as rings, disks and shafts. The properties of SiC_f/Ti composite mainly depend on SiC fiber, titanium alloy matrix and fiber/matrix interface. The microstructure and properties of SiC fibers are highly sensitive to the preparation process, and it is one of the research focuses to obtain stable SiC fibers by regulating the reactor structure and deposition conditions. The titanium alloy matrix can be coated on the fiber surface by physical vapor deposition to prepare the titanium alloy precursor wire, which is the key to the subsequent preparation of high-quality components. The interfacial microstructure, thermal stability and mechanical properties of SiC_f/Ti composites are closely related to the coating on the fiber surface, so the control of coating type and structure is an important means to control the interfacial properties of SiC_f/Ti composites. The application of SiC_f/Ti composite materials has promoted the development of non-destructive testing technology, so researchers have carried out the basic research of ultrasonic testing, X-ray testing and acoustic emission in application of composite material testing. In order to realize the wide application of SiC_f/Ti composites, further research work should be carried out in the structural design, low-cost manufacturing, failure analysis and life prediction of composite materials in the future.

The rapid development of aviation equipment such as hypersonic aircraft has put forward higher requirement for the comprehensive properties and application levels of titanium alloys. The properties of titanium alloys prepared by traditional thermal technologies have approached or reached the theoretical limit. Traditional technologies have been difficult to greatly improve the comprehensive properties of titanium alloys, and exploring graphene technology to modify titanium alloys has become an important development direction. However, it is difficult to control the interface reaction of graphene in titanium alloys. How to obtain the graphene/titanium interfaces with high bonding strength is the key to improve the performance of graphene reinforced titanium matrix composites. Based on the analysis of the problems restricting the development of graphene reinforced titanium matrix composites, this paper emphatically introduces the research progresses of microstructures, interface characteristics, static/dynamic mechanical properties, friction and wear properties, oxidation resistances, and strengthening and toughening mechanisms. The advantages and disadvantages of current solutions for dispersion uniformity, interface bonding and microstructure compactness are discussed. The challenges of interface control technology, large-scale preparation technology and performance stability of graphene reinforced titanium matrix composites are pointed out. Finally, it is proposed that such materials should be combined with theoretical calculation technologies, advanced preparation technologies and special function applications to deepen the interface optimization design and controllable preparation, and the application field expansion.

Titanium alloys are widely used in the manufacture of aero-engine blisks due to their low density, high strength, and excellent performance at medium and high temperatures. However, there are few studies on dynamic mechanical properties and adiabatic shear sensitivities of titanium alloy forgings for blisks. In this work, the dynamic mechanical properties of forged TC17 and TC4 alloys at high strain rates were examined by SHPB apparatus, and OM, SEM, EBSD were used to study the adiabatic shear behaviors of the two kinds of alloy. As the strain rate increases, the strength of both alloys increases, thus exhibiting the strain rate strengthening effect. At the same strain rate, TC4 alloy exhibits higher plastic strain and dynamic absorbed energy than those of TC17 alloy. TC17 alloy obtains a basket-weave microstructure after β forging, in which lath α-phases and residual β phases form more phase interfaces. ASBs tend to form at phase interfaces, which lead to a tendency for ASBs to bifurcate during propagating processes. TC4 alloy obtains a bimodal microstructure after α+β forging, and equiaxed primary α-phases show good ductility, which improve the dynamic plastic deformation ability. The regular arrangement of secondary α-phases results in fewer phase interfaces, leading to the difficulty in bifurcation of ASBs during propagating processes. Under dynamic interrupted compression conditions, ASBs in TC17 alloy are occurred earlier, and the localization energy of ASBs is low. Therefore, TC17 alloy has higher adiabatic shear sensitivity, and adiabatic shear sensitivities of both alloys increase with the increase of strain rates.

Aiming at the problem that the fatigue performance of aeroengine blade leading edge was seriously degraded after foreign object damage（FOD）, the surface of TC4 titanium alloy thin wall specimen was treated by laser shock/mechanical shot peening, and the residual stress gradient distribution on the specimen surface before and after the composite strengthening was measured by X-ray diffraction method; The high order vibration fatigue life of TC4 titanium alloy thin wall specimens before and after treatment was tested by electromagnetic vibration table, and FOD was introduced into the specimen surface by fabricating pits of different shapes with a hardness tester; The fatigue fracture surface was analyzed by SEM; The evolution of residual stress distribution on the specimen surface before and after FOD was simulated by finite element dynamic numerical simulation, and the mechanism of the influence of the composite strengthening layer on the notch fatigue performance of FOD was revealed. The results show that the average fatigue life of the composite strengthened FOD specimen is 370% and 60% higher than that of the non strengthened FOD specimen and the non strengthened FOD specimen, respectively. The deep residual compressive stress field（thickness 500 μm）formed on the surface layer of the specimen after composite strengthening is an important reason for increasing the fatigue life of FOD specimen.

Continuous SiC fiber reinforced titanium matrix composite（SiC_f/Ti composite）has good specific strength and comprehensive mechanical properties, it is a lightweight high temperature structural material that attracts much attention in the new generation of equipment development. SiC_f/Ti composites can be prepared by the methods of foil fiber foil（FFF）and matrix coating fiber（MCF）. In order to compare the effects of the two methods on the growth of interfacial reaction, SiC_f/TC17 composites were prepared by FFF and MCF respectively. By study the interfacial reaction layer thickness of composites prepared by the two processes after thermal exposure at the temperature from 800℃ to 900 ℃, the microstructure and the thickness of interfacial layer were analyzed by scanning electron microscope, further the interfacial reaction rate at high temperature was obtained, and the interfacial reaction kinetic parameters of different materials were attained. The results showed that the interfacial reaction rate of SiC_f/TC17 composite prepared by MCF method was higher than that of the composites prepared by FFF method at the same temperature. The interfacial reaction rate factor k₀ is 4.942×10⁻³ m/s^1/2 and 8.149×10⁻³ m/s^1/2 for the composites prepared by MCF and FFF method, respectively. Additionally, the reaction activation energy Q is 276.3 kJ/mol and 291.7 kJ/mol for those, respectively. This is because the titanium alloy matrix prepared by MCF method has smaller phase structure and higher element diffusion rate at high temperature. Therefore, the composite prepared by MCF has lower reaction activation energy at high temperature.

High speed cutting is an effective technique to achieve high efficiency and high quality machining of titanium alloy and other difficult materials. The high speed cutting process of titanium alloy has the nonlinear dynamic characteristics of high temperature, high strain and high strain rate. In order to accurately describe the dynamic mechanical behavior of titanium alloy in high speed cutting, the research on dynamic constitutive model of titanium alloy is reviewed. The application conditions, advantages and disadvantages of Johnson-Cook model, Zerilli-Armstrong model and Bammann model are analyzed from the perspective of phenomenological model and physical model with Ti-6Al-4V as the research object. After comprehensive comparison, the Johnson-Cook model is selected for further exploration, and the Johnson-Cook modified model is classified based on the influence of temperature and competition mechanism. The prediction accuracy of the Johnson-Cook modified model is improved compared with that of the classical model. At the same time, it is proposed that the construction of phenomenology-physics composite constitutive model can be taken as the key direction to explore the dynamic constitutive model of titanium alloy, and the method of experiment and computer synchronization can be used to obtain the optimal solution of constitutive model parameters, so as to improve the prediction accuracy of dynamic constitutive model.

α+β titanium alloys have a wide application prospect in aero engine blisk manufacturing, owing to their high specific strength and good high-temperature performance. Whereas there are few studies on mechanical properties and plastic deformation modes of large-size blisk specimens at variable strain rate conditions. In this work, the effects of different strain rates on the mechanical properties of forged TC17 and TC4 alloys were examined by tensile testing machine, and Vickers hardness tester, OM, SEM, and EBSD were used to study the Vickers hardness, deformation microstructures and fracture morphologies. As increasing strain rate, the strengths of both alloys increase and the elongation decrease, showing positive strain rate sensitivities of flow stress, and the strain rate sensitivity coefficients decrease with true strain. Besides the solid solution strengthening of alloying elements, lath α-phases and residual β-phases in TC17 alloy with basket-weave microstructure are interweaved with each other, resulting in more phase interfaces. Phase interfaces are effective in blocking dislocations motion and lead to pile-up of dislocations, improving the strength of TC17 alloy. In addition, the voids are easier to nucleate at the phase interfaces and form dimples. Therefore, a lot of small dimples are observed on the fracture surface, which make the poorer ductility of TC17 alloy. Fewer phase interfaces exist in TC4 alloy with bimodal microstructure, which is related to the better plastic deformation capacity of equiaxed primary α-phases and the regular arrangement of secondary α-phases in transformed β-phases. The fewer phase interfaces increase the mean free path of dislocations and form fewer large dimples, which lead to a decrease in strength but an increase in ductility of TC4 alloy.

Aiming at improving the strength-plasticity match in the as-cast state of the most widely used Ti-6Al-4V the present work designs Ti-Al-V-Zr alloys on the basis of the dual-cluster formula of Ti-6Al-4V, α-{[Al-Ti₁₂]（AlTi₂）}₁₂ +β-{[Al-Ti₁₄]（V₂Ti）}₅: first, the alloys are more biased towards α-Ti by decreasing the number of β unit to 2, then, the stability of β-Ti is improved by increasing the number of V atoms in β unit to 3, and finally, Zr （x=1-5） replaces Ti in the β unit. Finally α-{[Al-Ti₁₂]（AlTi₂）}₁₅-β-{[AlTi_14-xZr_x]V₃）}₂ is obtained, Ti-（6.64-6.82）Al-（2.42-2.35）V-（1.44-7.02）Zr （mass fraction,%） alloy is designed. The alloy ingots are prepared by melting in a non-consuming vacuum are furnace, and the alloy bars are suction-cast in copper mould. The results show that the alloys are all in α' martensite structure, showing morphologies changing from acicular Widmannstatten structure at lower Zr contents to net-basket structure at higher Zr contents. Among the designed alloys, Ti-6.64Al-2.35V-7.02Zr （x=5） with a net-basket structure, has the best mechanical properties: yield strength of 806 MPa, tensile strength of 963 MPa, and elongation of 5.9%, which are respectively 23%, 19% and 51% higher than those of Ti-6Al-4V alloy under the same preparation condition. In particular, the specific strength and specific hardness are 217kN•m/kg and 0.71 GPa•cm³/g, which are 18% and 10% higher than Ti-6Al-4V alloy.

Wire arc additive manufacturing (WAAM) is an additive manufacturing technology with high deposition rate that produces a variety of high-performance metal structures layer by layer stacking. The research on WAAM technology of large and medium complex aluminum alloy and titanium alloy for aviation equipments has been widely concerned. In this paper, the WAAM technical definition, classification, forming system and principle are discussed. The recent research progress in the microstructure properties, metallurgical defects, quality improvement and technical application of typical components of aluminum alloy and titanium alloy formed by WAAM in aerospace field both at home and abroad is reviewed. The key common problems in the WAAM forming large and medium complex components of aviation equipments are analyzed, and the 2035 WAAM forming technology route planning map is proposed. In 2035, the "shape control" and "property control" technology of WAAM aluminum alloy and titanium alloy component is to be mastered; the large and medium complex structure components of aluminum alloy and titanium alloy which formed by WAAM are achieved comprehensive application in aviation equipment.