In this paper, the forming technology of titanium alloy plate was summarized, the control points of the rolling process of titanium alloy plate with different structure types (equiaxed structure, full lamellar, basket wave structure) were summarized, the present situation and problems of the forming technology of titanium alloy plate were analyzed, and the solutions are given. By combing the forming technology of near α titanium alloy, α + β titanium alloy and β titanium alloy, the microstructure and texture characteristics of rolling process of plate were analyzed, and the mechanical properties of plate with different microstructure types were compared. The control methods of precipitation, microstructure, texture and properties of titanium alloy plate were proposed, and the key control points of forming technology of titanium alloy plate were expounded. The existing problems of titanium alloy plate products, including warp degree problem, large residual stress, the instability of ultrasonic inspection level and so on, were analyzed, and specific solutions were given. Finally, three research priorities and two development directions of domestic titanium alloy sheet and plate forming technology were prospected in order to promote the specific manufacturing of key products and the standard operation level of conventional products of titanium alloy sheet and plate.

Functional gradient ceramics (FGC) are novel ceramic materials that integrate structure and function, enabling the material’s composition and properties to continuously vary as needed. FGCs have broad application prospects in fields such as aerospace and biomedical engineering. Laser directed energy deposition (LDED) technique overcomes the obvious limitations of conventional preparation methods in terms of sintering deformation and transition interfaces, which achieves regionally controllable properties of FGCs. However, optimizing the performance of different components simultaneously through constant parameter fabrication is not feasible. Therefore, the effect of scanning speed on the composite ceramic materials with various proportions in Al₂O₃–ZrO₂gradient ceramics was investigated. By determining the optimal scanning speed for each composite ceramic, the optimal fabrication of Al₂O₃–ZrO₂ gradient ceramics with variable parameters was achieved. The results show that under low scanning speed conditions (200 mm/min, 300 mm/min), the α-Al₂O₃ columnar crystals exhibit obvious growth orientation tendency, and macroscopic cracks are apparent in composite ceramics with high ZrO₂content. The gradual increase of scanning speed helps to reduce the grain size and thus improve the mechanical properties of the fabricated sample, but too high scanning speed leads to more internal defects and decreases the performance. The variable scanning speed fabricating process effectively suppresses the macroscopic cracks with high ZrO₂content in the gradient region. In addition, the macro and micro cracking defects at the bonding interface of Al₂O₃–ZrO₂gradient ceramics with constant parameters are improved. The flexural strength at the transition interface of optimally manufactured Al₂O₃–ZrO₂ gradient ceramics is improved by 21.37%.

Additive manufacturing (AM) is an advanced manufacturing technology based on the principle of“ discrete stacking”, which drives the additive equipment to realize rapid manufacturing of parts through data pre-processing, slicing and path planning of the three-dimensional digital model, and generating the recognizable execution code of the additive system. AM has been widely used in aerospace, automobile, shipbuilding, medical, construction and other industries in recent years. Slicing and path planning are the core steps of data processing for 3D digital model of additive manufacturing, which determines the process variables, part shape accuracy and performance of the manufacturing process. Firstly, the research progress of slicing method based on various digital models such as CAD model, point cloud model, STL model, voxel model, etc. in additive manufacturing is reviewed, and comments were made on the generation accuracy of each model, the principle of slicing algorithm, and algorithm efficiency; Secondly, various slicing algorithms such as equal thickness, variable thickness, variable direction, and partition combinations for planar and nonplanar surfaces, as well as various path planning algorithms for planar single region, multi region, local features, and nonplanar surfaces are reviewed. The design points of slicing and path planning algorithms are analyzed and sorted out preliminary; Finally, the current research status of planar and nonplanar slicing and path planning in additive manufacturing digital models is summarized, and its development trends are prospected.

Dense silicon nitride ceramics were prepared innovatively based on the fused deposition modeling (FDM) method with granular feedstock via screw extrusion. The printability of the feedstock, debinding process and typical printing defects were studied. The results show that the feedstock possesses an excellent printing performance and fits for printing unsupported small inclination angles, thin walls and complex curved surfaces. The organic binder system developed in this study combined with a two-step, “solving + heating” dedinding process has outstanding advantages in the preparation of thick-section parts and can achieve safe degreasing of green bodies with a thickness of 9 mm. It was revealed that the typical process defects of FDM include interlayer cracks and interpath pores. Combined with gas pressure sintering, dense silicon nitride ceramics with a bending strength of (774.5±70) MPa and a density of 3.25 g/cm³ were prepared, and silicon nitride ceramic parts with complex shapes and good shape keeping were successfully prepared.

Continuous fiber reinforced composites have long been favored in fields such as aerospace and automotive industry due to their advantages of lightweight, high strength, and high design freedom. To achieve rapid, personalized, and complex structural manufacturing of continuous fiber reinforced thermoplastic composites, and break through the limitations of traditional manufacturing methods, the use of 3D printing technology to prepare continuous fiber composite materials is considered an effective approach and has received widespread attention and research. Therefore, the basic principles, method classification, and research progress of 3D printing technology for continuous fiber reinforced composite were elaborated, and the development was reviewed from the aspects of forming materials, forming processes, forming properties, and forming mechanisms. Prospects for 3D printing of hybrid continuous fiber reinforced composite, multidegree-of-freedom 3D printing and their path planning research were proposed.

Thin-walled stiffened composite structures have gradually been used in aerospace, naval vessels, extreme engineering and other high-end equipment due to their light weight, high strength, corrosion resistance, fatigue resistance and other advantages. This article reviews recent progress in terms of structural design of thin-walled stiffened structures, additive manufacturing processes for composite materials, and applications of thin-walled stiffened composite structures in high-end equipment. For the structural design of thin-walled stiffened structures, the methods including parametrization method, shape optimization method, topology optimization method, and other advanced methods are outlined. The development of composite additive manufacturing, such as filament winding, automatic fiber placement and 3D printing technology, and fiber path planning methods are discussed. Then, typical applications of thin-walled stiffened composite structures in the field of high-end equipment are sorted out. Moreover, the development trend and challenges of the design and manufacturing of thin-walled reinforced composite structures are summarized. Finally, we summarize the development trends and challenges in structure-process integrated design of thin-walled stiffened composite structures.

Sleeve taper-hi-bolts’ performance, double lap joints’ static strength and fatigue test were carried out, and failed joints were analyzed. The results show that sleeve taper-hi-bolts’ tensile, double shear and fatigue performance are qualified, and tensile fracture surface shows characteristics of dimple. Proportional difference of the pin load distributions for clearance fit is 41% for composite laminates with aluminum plates, while 34.7% for 1.0% interference joints. For composite laminates with titanium plates, proportional difference of the pin load distributions for clearance fit is 43.3%, while 37.7% for 1.0% interference joints. The fatigue life of interference fit composite laminates with aluminum plates is 1.7 times that of clearance fit, while 3.4 times for composite laminates with titanium plates. The main crack of interference fit joints originates from the angle of the hole, and that of clearance fit joints originates from the hole wall. Fracture analysis shows that 7050 exhibits mixed-rupture characteristics of quasi-cleavage and dimples, while TA15 exhibits quasi-cleavage characteristics with equiaxed dimple and river pattern.

Laser peening has broad application prospects in the aviation manufacturing industry. Research on its strengthening mechanism is important for understanding the response of materials under laser peening and rationally planning the laser peening process. Electron backscatter diffraction and X-ray diffraction were used to characterize the microstructure evolution, and to analyze the microstructure strengthening mechanisms. The effect of laser peening on the mechanical properties of the aluminum alloy was studied through the tensile test of the 2024 – T351 aluminum alloy samples after laser peening. The results show that laser peening induces grain refinement in the rolling direction and generates low-angle grain boundaries by deformation strain gradient, and at the same time induces multiplication of statistical storage dislocations. Laser peening mainly improves the material strength through dislocation strengthening, and the grain refinement strengthening and the solution strengthening mechanisms do not contribute significantly.

In order to explore the distribution of residual stress field in TC17 titanium alloy with ultrasonic shot peening, an ultrasonic shot peening vibration system was established based on ABAQUS/Explicit. Combined with simulation and experiment, the stress field, surface morphology and strain layer distribution of TC17 titanium alloy with 0.15 A and 0.25 A shot peening intensities were investigated respectively. Under two shot peening intensities, the maximum value of compressive residual stress is all in the sub-surface region. There is a small difference between the value of simulation and the test in the mean value of residual stress on the surface, the maximum value of compressive residual stress on the sub-surface and the depth of residual stress layer, and the overall deviation is less than 15%. With the increase of shot peening intensity, the concentrated distribution of Schmid factor tends to decrease. Under shot peening intensity of 0.25 A, the depth distribution of strain layer and compressive residual stress layer is similar, increasing by 57.1% and 53.3% compared to 0.15 A respectively. High cycle fatigue results show that, compared with 0.15 A, 0.25 A shot peening intensity fatigue limit increases by 4.7%, and the fatigue life under two kinds of shot peening intensities achieve 107 cycles. The depth of compressive residual stress layer has little effect under high load and low cycle, and inhibition of crack initiation increases under low load and high cycle. Higher surface compressive residual stress and depth of compressive residual stress layer have more significant effects on restraining fatigue caused by tensive residual stress.

The role of elastic vibration honing finishing on surface integrity of 16Cr3NiWMoVNbE gear was experimentally examined, by comparing profile feature of tooth chamfering, surface morphology and roughness, crosssectional metallurgic microstructure and microhardness, surface residual stress. Compared to the gear without finishing, elastic vibration honing has improved the chamfering profile, decreased surface roughness and promoted surface residual compressive stress. Such improvements increased with prolong finishing periods of elastic vibration honing. After prolonging for twice times of finishing period, arc transition at crest chamfer and fine mesh strips have been achieved. Moreover, the surface roughness has been decreased from Sa0.47 μm to Sa0.2 μm, and the average surface residual compressive stress has been enhanced by 52%. The results give a reference for process design of elastic vibration honing finishing on hard-machining aircraft gears.