Equiatomic Ni-Ti alloys have been widely applied in biomedical and industrial fields, because of their shape memory effect and superelasticity originating from thermos-elastic martensitic transformation. The theoretical and experimental studies in recent years indicated that when doping sufficient amounts of defects (excess solute atoms, foreign alloying dopants, dislocations and nanosized precipitates) into equiatomic Ni-Ti alloys, the resistance from such defects could suppress the first-order martensitic transformation and achieve strain glass transition with the formation of randomly short-range ordered nanodomains. The strain glass transition is characterized by some typical features such as invariant macroscopic structure, broken ergodicity, frequency dependence of dynamic mechanical properties and high damping capacity. In spite of no first order martensitic transformation occurred during cooling, strain glass can exhibit unique shape memory effect and superelasticity because of the stress loading induced transformation from strain glass to martensite and the reversed transformation by stress unloading. The superelasticity of strain glass alloys are closely related to the type and concentration of defects. The strain glasses with moderate concentration of defects exhibit the superelastic behavior similar to conventional Ni-Ti based alloys. By contrast, under temperature or/and stress fields the strain glass ↔ R transition could occur in the strain glasses with high concentration of defects, leading to the superelasticity with small recovery strain and slim hysteresis over a broad temperature range. Strain glass transition could be achieved in Ni-Ti alloys by deformation to introduce large number of dislocations. If only the evolution of nanodomains is involved and no B19′ martensite forms in the Ni-Ti strain glass under external stress, the alloy could perform large linear superelasticity with slim hysteresis. The underlying mechanism for such superelastic behavior lies in that under stress the evolution of nanodomains does not need nucleation, and the energy loss for nucleation can be avoided. In the present paper, the proposition, novel properties and the research progress of the strain glass transition in Ni-Ti based alloys were reviewed. The principle for designing Ni-Ti based alloys with superelasticity in wide temperature range and their applications in engineering are briefly introduced.

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.

Light-curing 3D printing technology stands out as one of the oldest, fastest-growing and most widely used technologies in the field of 3D printing. This technology utilizes ultraviolet or other light sources to rapidly solidify liquid photosensitive polymers, creating products with complex geometrical structures that are difficult to achieve with traditional manufacturing methods. This paper summarizes the latest research progress in photocurable polymer materials for 3D printing, covering various types of photocurable polymers including thermoplastics with high remoldability, thermosets with good structural stability, and hydrogels with hygroscopic network cross-linking structures. Additionally, the applications of photocurable 3D printing polymers in various fields such as biomedical, flexible electronic devices, soft robotics, energy storage, and aerospace are discussed in detail. This review also explores the application of photocuring technology in 4D printing, highlighting the potential of 4D printing in dynamic materials and smart manufacturing. In the future, light-curing 3D printing technology is expected to advance toward the development of high-performance polymer composites, the integration of intelligent and automated printing systems, and the deep integration with cutting-edge technologies such as artificial intelligence, continually driving its applications and innovations in high-tech fields and advanced manufacturing.

Constant-amplitude fatigue tests were conducted on overlap specimens of 7075/6061 aluminum alloy TIG fillet weldes. Subsequently, detailed finite element models were developed based on both the hot spot stress method and the critical distance method. The range of maximum principal stress variation was from these models as a fatigue evaluation index for further analysis. By combining the results of finite element stress-strain analysis with the S-N curve recommended by the International Institute of Welding (IIW), the fatigue lives of the weld joints under various loadings were estimated. Testing revealed that specimens primarily fractured at the weld toes on the 7075 side. The maximum stress-strain concentration points in the finite element model were located at the weld toe on the 7075 side, aligning closely with the actual fracture locations. By comparing the predicted fatigue lives with the actual test results, it was determined that the hot spot stress method can predict the fatigue life of TIG welds more accurately. After correcting for plate thickness, the prediction errors were within a factor of two in the low-cycle fatigue range. Both the point method and the line method within the critical distance method can predict hot spot stress, but the point method yields more precise results than the line method.

The service life of single crystal turbine blades, which serve as pivotal components in aero-engines, is intricately tied to their surface integrity. To fulfill performance standards, these blades typically undergo shot peening to meet for reinforcement. This study meticulously examines the impact of surface morphology and various surface integrity indicators—including roughness, near-surface microstructure, hardness, and residual stress—on DD6 single-crystal superalloy before and after undergoing shot peening treatments of varying intensities (0.15, 0.2 mmA, and 0.25 mmA). Utilizing a surface profilometer, scanning electron microscope, microhardness tester, and stress tester, we comprehensively analyze these factors. The results show that shot peening diminishes the original machining marks on the DD6 superalloy’s surface, with surface roughness escalating from 0.507 μm at 0.15 mmA to 0.883 μm at 0.25 mmA. A gradient plastic severe deformation layer emerges near the surface, its depth progressively increasing from 45 μm at 0.15 mmA to 98 μm at 0.25 mmA. Furthermore, the surface hardness value rises steadily, from 490HV in the original specimen to 738HV at 0.25 mmA, with the hardened layer’s depth also augmenting, from 50 μm initially to 260 μm at 0.25 mmA. Notably, the alloy attains its peak residual compressive stress of approximately –821.2 MPa on the surface when subjected to a blasting intensity of 0.2 mmA.

For the gears of aero-engine accessory system, the complex working environment requires high fatigue resistance and wear resistance on the gear surface. Laser shock peening technology introduces residual compressive stress and high micro-hardness by severe plastic deformation on the material surface. A more uniform residual stress field and hardness distribution are crucial to improve the fatigue life and wear resistance of the parts. Thus, it is an important topic to investigate how to obtain a uniform residual stress field and hardness distribution by optimizing the technical parameters of laser shock peening. In this paper, a four-layer overlapping laser shock peening path scheme is proposed, and the spatial distribution characteristics of residual stress and micro-hardness after laser shock peening are analyzed by the finite element numerical simulation and experiment. Using finite element numerical simulation method, the spatial homogeneous distribution of the residual stress field after the multi-point laser shock peening is studied. The effects of laser energy and impact times on the residual stress and micro-hardness of gear steel are experimentally investigated. The results show that the proposed four-layer overlapping laser shock peening path scheme can obtain a more uniform surface residual compressive stress field. With the increase of laser energy and impact times, the surface residual stress and micro-hardness also increase, but the increase magnitude will decrease, showing a certain saturation trend.

The creep rupture properties of DD419 single crystal superalloys, fabricated at varying pouring temperatures were examined under conditions of 850 ℃/650 MPa, 1050 ℃/190 MPa and 1100 ℃/130 MPa. SEM, EDS and TEM were used to analyze the microstructure and component segregation to study their effects on the durability. The results show that as the pouring temperature decreases, the primary dendrite spacing of the alloy widens, the eutectic content and the number of micropore increase, and the γ′ phase size diminishes. Under high temperature/low stress（1100℃/130 MPa）, the γ′ phase size exerts a more pronounced influence on durability than do micropore and residual eutectic content. The finely dispersed γ′ phase enhances the alloy’s durability under all three test scenarios, with the alloy poured at 1500 ℃ exhibiting optimal durability. At intermediate temperature/high stress condition（1050℃/190 MPa）, the γ′ phase is intersected by numerous dislocations, and dispersed γ′ phase may contribute to dislocation pile-ups. Concurrently, the alloy maintains good elongation at different pouring temperatures; however, as the pouring temperature decreases, section shrinkage decreases under all three test conditions. Pouring temperature has a negligible impact on the the alloy’s fracture morphology. Specifically, the γ′ phase near the fracture surface of the specimen tested under 850 ℃/650 MPa condition remains cubic morphology, with a mixed -mode fracture mechanism. Under other durability parameters, the γ′ phase assumes a rafted configuration, leading to an all-micropore aggregation fracture mechanism.

Carbon fiber reinforced polymer（CFRP）composites has small and hidden damage after low-speed impact, and the existence of damage significantly reduces the bearing capacity and service life of CFRP materials. C-scan represents a conventional ultrasonic imaging method. To address the issue of low imaging precision in C-scan detection of internal damage caused by low-velocity impact in CFRP, gradient operators were employed to process the original images, and transfer learning methodology was utilized to conduct damage classification training on ResNet18 and ResNet50 architectures. To enhance the classification model’s performance, an image reconstruction model（IRM）based on convolutional neural networks was proposed to improve imaging precision. Additionally, a performance metric σ_EOL, based on the structural similarity index（SSIM）, was introduced to validate the level of image quality enhancement. The iterative training results demonstrate that when the iteration count reaches 200, the σ_EOL of different types of impact damage is greater than 1. To further improve imaging precision, the ResNet residual connection concept is incorporated, leading to the development of the ResIRM network. Compared to IRM, ResIRM exhibits enhanced detection precision for different types of impact damage, with an average σ_EOL improvement of 0.85% across all impact types. Furthermore, the gradient saliency heat maps of the classification model processed by ResIRM indicate that ResIRM effectively reinforces the features in damaged regions.

To provide technical support for the design of new seamless flexible trailing edge structures, a comparative study of the elastic properties of four novel zero Poisson’s ratio honeycomb structures（sinusoidal-type, V-type, segmented sinusoidal-type and cosine-type）is conducted through theoretical analysis and finite element simulation. A tensile test on the cosine honeycomb is also carried out. Based on this, a flexible trailing edge based on a two-dimensional deformable zero Poisson’s ratio cosine honeycomb was designed, and the bending performance of the cosine honeycomb trailing edge section is simulated and analyzed. The results show that the in-plane elasticity and stress state of the cosine honeycomb structure are superior to other three honeycomb structures. The quasi-linear strain of the cosine honeycomb achieves 27.8%. Excellent bending performance of cosine honeycomb segment can be achieved by parameter adjustment, thereby achieving significant bending deformation of the flexible trailing edge structure. This study can provide references for the design and analysis of novel flexible trailing edge structures.

In the co-curing process of aramid honeycomb sandwich structures with traditional hexagonal core lattice structures, the deformation compatibility of honeycomb with locally varying structures outside the plane is an important factor affecting the internal forming quality of sandwich structures. This article analyzes the out-of-plane local deformation performance of honeycombs using numerical methods by establishing a finite element quantitative analysis model, combining typical structural experimental verification methods, using full-body modeling and elastic mechanics plate bending theory. It explores the influence of key factors such as honeycomb thickness and external pressure on honeycomb deformation, and verifies the local surface fitting method of super-honeycomb deformation limits. The results show that the quantitative analysis model of aramid honeycomb deformation capability, with deflection deformation fitting as the core, has good applicability for predicting the matching state of honeycomb-layered structures. For cases where the slope of the honeycomb deflection fitting curve is less than the transition slope of the layer, honeycomb yield milling has a positive impact on the bonding quality of the transition region of the layer, but different forms of yield milling do not produce significant differences in bonding quality. The relevant results have certain reference value for structural design and process design of honeycomb sandwich structures.

Nanomaterials can greatly improve the mechanical properties and corrosion resistance of epoxy resin, and the use of nanomaterials to modify epoxy resin is an important research direction in the field of coatings. Fusible bonded epoxy resin (FBE) was modified by ZSM-5 molecular sieve, reduced graphene oxide (rGO) and their interaction (ZSM-5-rGO). The effects of FBE on microhardness, adhesion and corrosion resistance were studied. The results show that the microhardness of ZSM-5 modified fused epoxy resin is increased by 44%. The microhardness value of rGO modified fused epoxy resin is increased by 25.7%, and its corrosion resistance is improved from 6421 Ω·cm² to 75371 Ω·cm². ZSM-5-rGO modified fused bonded epoxy resin has good corrosion resistance and improves the binding force with aluminum alloy matrix by nearly two times. When the ratio of ZSM-5 to rGO is 2∶1, the comprehensive modification effect of ZSM-5 on fusion bonded epoxy resin is the best, the microhardness is 38.84, and the binding force with aluminum alloy matrix is 67.5 N.