To content large part manufacturing of the airplane, electron beam welding (EBW) was employed on TC4 titanium alloy with 170 mm thickness, which was investigated by the method of induced molten pool flow. The experiments with variable focusing welding were conducted on the plates, which achieved the underfocusing processing under the current of 2415–2400 mA. The maximum of welding depth reaches 162 mm, and weld morphology is parallel, which contributing to the fluidity of molten pool and welding formation. The microstructures in weld area are coarse crystals and acicular martensite α', which became gradually refining and homogeneity with the welding penetration increasing. The microhardness of the joint presents the saddle-shaped distribution along the cross section, which gradually increases from 337HV to 356HV along welding depth direction. The investigation verified effectiveness of the EBW processing with induced molten pool flow, which can improve the penetration forming, weld morphology, and microstructure uniformity of large-thickness titanium alloys.

The demand for functional metal patterning on dielectric surfaces has been growing rapidly, driven by applications in aerospace, consumer electronics, and flexible sensing technologies. As a mask-free and flexible technique, laser manufacturing provides high precision, non-contact processing, and high efficiency, making it ideal for directly fabricating functional metal patterns on various dielectric surfaces. In recent years, significant progress has been made in this field. This review classifies six primary laser manufacturing techniques for metal patterning on dielectric surfaces into two main categories: top-down and bottom-up approaches. These include laser ablation, selective laser sintering, pulsed laser deposition, laser-induced chemical liquid deposition, laser-induced chemical vapor deposition, and laser-assisted electroless plating. The principles, advantages, and recent developments of each technique are discussed, along with an exploration of the technical challenges and future directions for development in this evolving field.

With the rapid progress of science and technology, difficult-to-machine materials and parts with special-shaped surfaces have been widely used, and traditional cutting techniques are difficult (or unable) to solve the emerging processing problems. Special processing methods such as ultrasonic, laser, electrical discharge and electrochemical machining can effectively solve technical problems. Each single processing technology has its own advantages, but also has its limitations. For example, cutting high-hardness materials is difficult. Ultrasonic machining is only effective for hard and brittle materials. The overall efficiency of electrical discharge machining (EDM) and wire-cutting is relatively low, and there is a surface deterioration layer. The accuracy of conventional-parameter electrochemical machining is not high enough, and there are environmental protection issues. In practice, the multi-energy field processing method has the advantage of multi-technology compounding. This paper systematically analyzes and reviews the mechanism and application status of multi-energy field processing such as ultrasonicassisted cutting, ultrasonic-assisted laser, ultrasonic–compounded electrical discharge, ultrasonic–compounded electrochemical machining and ultrasonic–compounded mechanical–electrochemical–electrical discharge. Ultrasonic-assisted cutting can significantly reduce the cutting force and heat, improve chip evacuation conditions, minimize (or avoid) surface defects, and effectively enhance machining accuracy and efficiency. Ultrasonic-assisted laser processing can effectively solve the problems of product removal and surface quality. Ultrasonic–compounded electrical discharge machining not only ensures machining accuracy but also significantly enhances machining efficiency. In addition, the polishing effect of ultrasound can improve the surface quality of electrical discharge processing. The ultrasonic effect can enhance and improve the effect  of the electrochemical inter-electrode action and increase the nonlinearity of the electrochemical material removal. The ultrasonic-compounded electrochemical machining can significantly improve the processing accuracy. The multi-energy field machining methods of ultrasonic-compounded mechanical–electrochemical–electrical discharge have the interaction of parameters that can “retain the advantages and eliminate the disadvantages”, have the advantage of multi-technology compounding. Through the optimization and coordination of the parameters of the multi-energy field, the difficult-toprocess parts of different performance materials can be optimized. The paper systematically summarizes the characteristics, technical indicators and practical applications of ultrasonic – compounded mechanical–electrochemical–electrical discharge multi-energy field machining, analyzes the existing problems, discusses the effective solutions, and analyzes and prospects the relevant research work in the future.

In the field of aerospace defense, 2.5D C/SiC composites are crucial materials for high-temperature resistant components. The high hardness and wear resistance of these materials render the high-quality micro-hole machining exceptionally challenging. A picosecond laser drilling process for 2.5D C/SiC composites based on magnetic field/liquid-assisted machining (MLM) was proposed. By extracting the characteristics of micro-hole inlet/outlet diameter, taper, oxidation, and recast layer, a comparative study was conducted between MLM and three processes: picosecond laser machining (PM), magnetic field-assisted machining (MM), and liquid-assisted machining (LM). The results demonstrate that the picosecond laser machining based on MLM can effectively reduced the inlet diameter of the micro-holes while increasing the outlet diameter, achieving a micro-hole taper of 1.3° and 1.1° under two different sets of experimental parameters, the taper is reduced by 18.75% and 45% compared with PM process, reduced by 13.33% and 31.25% compared with MM process, reduced by 91.22% and 79.63% compared with LM process, respectively. Furthermore, microstructural analyses of the drilled micro-holes were performed using EDS spectroscopy, Raman spectroscopy, and XPS techniques. It was found that the MLM process more effectively reduced the graphitization defects on the hole walls. Among them, liquid-assisted machining avoids oxidation at the inlet of micro-holes, while clearly observing exposed fibers and matrix, effectively avoiding thermal damage and recast layer defects. In picosecond laser drilling, the primary mechanisms of MLM are attributed to the cooling effect of the liquid, its ability to isolate oxygen, and the longitudinal stretching of the plasma by the magnetic field, which reduces the plasma shielding effect.

To stress the issues of fabrication high-aspect-ratio small holes with low damage, high efficiency and high precision, laser and shaped tube electrochemical hybrid machining (Laser-STEM) has been proposed. In Laser-STEM, the laser is guided to the machining zone by internal total reflection through the hybrid tool electrode, in which the materials could be removed by laser processing at the center and electrochemical machining at the surrounding area synchronously, thus high-aspect-ratio small holes with high surface quality could be processed. The coupling method and mechanisms between the laser and hybrid tool electrode were studied. A high efficiency and stable laser transmission has been achieved. Feasibility of processing small holes with high efficiency and precision by Laser-STEM has been proven by observing the experimental phenomena and variation of the machining gap. Moreover, the relationship between the change of hybrid machining current signal and the machining state was established. Micro holes with a diameter of 1.25 mm, a depthdiameter ratio of 125:1, without recast layer and microcracks were processed on titanium alloy and nickel-based superalloy. The proposed hybrid processing method can be used for efficient and precise machining of micro holes with high surface quality and large aspect ratio for key components of aero-engines and gas turbines.

Laser processing technology is distinguished by its high degree of precision and versatility, which enables the processing of a diverse range of materials, including metals and non-metals. It has been employed extensively in industrial sectors, including aviation, automotive, and shipbuilding. However, conventional laser processing has certain limitations. These include the low efficiency of ultrafast laser processing, the thermal effects on the surface of conventional laser processing, and the formation of recast layers. In order to address these issues, laser liquid composite processing technology has emerged and flourished. The incorporation of liquid not only enhances the overall efficiency of laser processing but also markedly improves the quality of the resulting product. During the processing, the liquid fulfils the functions of a coolant, lubricant, and cleaning agent, effectively eliminating the heat-affected zone and recast layer. The implementation of liquid cooling and flushing facilitates the expeditious removal of processed products, thereby enhancing surface quality and further optimizing processing efficiency. This paper presents a comprehensive review of the latest research developments in the field of laser liquid composite processing, with a specific focus on water-assisted laser processing technology and electrolyte-assisted laser processing technology. Additionally, it provides an outlook on their future development directions.

According to the requirements of pulsed electron beam welding technology, the design of high-frequency pulsed electron beam bias circuit with adaptive closed-loop adjustment of beam current is realized by taking the structure design of fast controllable DC bias main circuit and the control circuit design of adaptive closed-loop adjustment of beam current as the core technology; The circuit parameters are simulated and verified by Cadence simulation software, and the circuit parameters are optimized. On this basis, a high-frequency pulsed electron beam bias circuit is developed, and its characteristics are verified by connecting it to the electron beam welding system. The results show that the pulsed electron beam can follow the set signal dynamically in real time, the working frequency can reach 1 kHz, the rising and falling speed of the beam is fast, the waveform is good and the distortion is small, which can effectively meet the requirements of the pulsed electron beam process.

Stray corrosion is an important factor affecting the precision electrolytic machining (PECM) accuracy of the blisk surface, and the auxiliary anode can effectively inhibit the stray corrosion of adjacent machined blades, thereby improving the machining accuracy of blades. In order to solve the problem that the narrow and twisted inter-blade channel of the blisk of small and medium-sized aero-engines leads to the difficulty of auxiliary anode design, an auxiliary anode structure design method was proposed, which realized the optimal design of the auxiliary anode by optimizing the feed path of the tool cathode. Results of the experiment research show that the auxiliary anode designed by this method can be fed to the starting position of the machining smoothly, and the surface of the machined blade is smooth, and there are no obvious traces of stray corrosion, which effectively improves the machining accuracy of the blisk.

The hot isostatic pressing (HIP) process of SiC/Ti60 composites was simulated using ABAQUS finite element simulation software. A representative volume element (RVE) model for SiC_f /Ti60 composites with a fiber volume fraction of 25% was established to analyze the hot isostatic pressing densification process and residual stress distribution characteristics of the composites. The analysis results show that the plastic deformation and densification of the composites mainly occur during the thermal and pressure holding stages, and the thermal residual stress characteristics of the interface layer are significantly different from those of the titanium alloy matrix and SiC fibers. The circumferential stress of the TiC reaction layer in the interface layer has a sudden change compared to that of the SiC fiber, and the compressive stress value increases by about 205 MPa. The axial stress on the C-coating and TiC interface layer approaches zero, reducing the stress gradient between the SiC fiber (compressive stress) and the substrate (tensile stress). The thickness of the C layer in composite materials can affect the thermal residual stress of the interface layer. When the thickness of the C layer increases from 1.5 μm to 2.5 μm, the radial stress in the interface layer and surrounding areas decreased by 7 MPa, and the circumferential stress in the TiC interface layer decreased by 20 MPa. Increasing the holding temperature of hot isostatic pressing can enhance the densification effect, but it will slightly increase the residual stress in the interface layer and adjacent areas.

The R-angle area of C-beam is prone to fold defects in the process of autoclave forming, which seriously affects the forming quality and service performance of the component. In order to accurately evaluate the degree of fold defects and provide ideas to reduce the generation of folds, C-beam samples of two different brands of prepregs at home and abroad under different layers were manufactured by using autoclaves forming process. The deformation behavior of R-angle prepregs in the forming process was analyzed and the mechanism of fold defects formation was explored. An evaluation method including thickness distribution, edge slip angle and R-angle quantitative analysis of partial folds is proposed, and the samples are evaluated and compared by using this method. The results show that the interlayer slip behavior of prepreg is the key mechanism of fold formation, and excessive slip resistance leads to fold defects. Compared with foreign prepregs, the tested domestic prepregs have greater overall viscosity, and C-beams manufactured are more prone to fold defects. The three evaluation indexes are consistent, and the degree of fold defect at R-angle of C-beam can be measured comprehensively from multiple angles.

Continuous fiber reinforced polymer composites (CFRPCs) is a new material in the field of additive manufacturing. Compared with traditional machining materials such as metals and ceramics, CFRPCs have the characteristics of light weight, high strength, fatigue and corrosion resistance. Therefore, it is widely used in aerospace, rail transit and biomedical and other fields. In recent years, with the development of additive manufacturing technology, CFRPCs 3D printing technology has opened up new ideas for the manufacture of high performance, low cost and customizable complex structural parts. This paper presents a comprehensive review of the CFPRCs 3D printing process, focusing on the latest research advancements in materials, process parameters, and performance enhancement techniques primarily based on the fused deposition modeling (FDM) process. It concludes with a summary and outlook on the current challenges and future developments in this field.

In response to the requirements for aircraft large component automatic and digital alignment and assembly, using advantage of the data connectivity and data value coming from the aircraft large component alignment and assembly process, a digital twin based technology framework for the aircraft large component alignment and assembly was proposed. Correspondingly, the technical process of the aircraft large component alignment and assembly was proposed and elaborated from four perspectives of data collection, model establishment, visual modeling and virtual to physical mapping. A light weight process has being used in the digital model of CATIA of the aircraft large component, then, a virtual space was built up based on Unity3D technology and the real time mapping of physical entities to virtual space was achieved by data collection and data central and application service. It provides a reference for the application of digital twin in the aircraft large component alignment and assembly.