With the rapid development of aerospace and weaponry, high efficiency and low cost manufacturing for large, integrated and high–performance metal component is in imperious demand. Wire and arc additive manufacturing (WAAM) is a kind of digital manufacturing technology with great potential to the industry. Compared to laser and electron beam additive manufacture, WAAM has many advantages, such as high material utilization, high deposition efficiency and low equipment cost. This paper provides an overview of researches of WAAM on macro forming accuracy, microstructure and mechanical properties of metal components, meanwhile, the main encounting problems of WAAM are also put forward. In order to solve these problems, the WAAM and its hybrid manufacturing technologies are reviewed, including ultrasonic peening or laser peening, cold rolling and hot rolling process, high–frequency micro–forging and post–treatment process. Finally, the key technologies to be solved of WAAM and its hybrid manufacturing are summarized.

    Radial force can cause vibration or deformation of workpiece in internal turning process, especially for deep hole turning, which have a negative effect on machining accuracy and surface quality. In this paper, the impact damper theory is investigated and the damped turning cutter is designed. Firstly, the impact damper theory is investigated via modeling and simulation based on Euler–Bernoulli beam theory. Then, the clearance and restitution coefficient are optimized via simulated annealing algorithm with different cutting parameters. The negative real part of the main mode of the damped turning cutter is maximized, which can achieve the stability of cutting process. Finally, the damped turning tool is designed based on impact damper theory and the cutting test is carried out. When n=400r/min, f=0.1mm/r, a_p=0.4 mm, the experimental results show that the vibration acceleration amplitude can be decreased from 46.5m/s² to 4.0m/s² and the roughness can be decreased from 4.62μm to 1.95μm.

    Most of the key components of aircrafts work in a complex loading environment that they are loaded by multi-axis force composed of tension or compression, bending moment and torque. The mechanical properties and fatigue life of key components have direct influence on the overall performance of the aeronautical system. Ensuring their safe and efficient service, it is necessary to test these properties under the load that close to the actual working conditions. In this paper, the elastomeric spheric thrust bearing (ESTB) is employed as the test object. Based on a 6–SPS parallel mechanism, a multi-axis loading device which is expected to simulate the ESTB’s actual working condition is developed. This device can load the ESTB with combined loading of pressure, bending moment and torque, and test the stiffness of the ESTB. The geometric parameters of the loading device were designed and its prototype was presented. Tests for compression, bending and torsional stiffness were conducted by the multi-axis loading device. Compared with the results obtained by traditional testing methods, the compression and torsional stiffness are in good agreement, but the bending stiffness is deviated because the traditional method didn’t eliminate the influence of axial force while applying bending moment. The tests prove multi-axis loading ability of the parallel mechanism. In addition, the stiffness characteristics of the ESTB under combined
pressure-torque is initially explored. Finally, the applications of the parallel mechanism in material tests and loading moving targets are discussed, and a multi-axis loading theory system for material, component and system could be formed.

    This paper introduces the manufacturing method of the middle fuselage plenum of the light business jet. The middle fuselage is a semi-closed cabin. Considering the detachable mold of the formed parts, and the ease of processing and forming, the tooling cannot be made into a whole. It is manufactured by using the upper and lower parts to solve the problem of insufficient space for parts. After the upper and lower molds are respectively laid and finished, the mold is formed by a co-solidification molding method. In this way, the bearing capacity requirements of the fuselage can be achieved, and the structural weight reduction can be achieved by 30%, and the foundation for the civil airworthiness road of the domestic main bearing composite component is laid. Compared with the original non-integrated fuselage structure, the fuselage of the composite material is co-cured, no fastener connection, no secondary bonding, reducing the number of tooling more than 100, simplifying the entire process of molding.

    Aiming at the problem that the data samples are small and nonlinear in the modeling of geometrical error items of CNC machine tools, the SVR (support vector regression) with unique advantages in the nonlinear regression analysis of small sample data sets is studied, and based on which the geometric error prediction model of CNC machine tools is established. This paper analyzes the problems of the difficulty of measuring points and the calculation of cumulative error in the nine-line method commonly used in the detection of geometric error, and then proposes an improved method to increase the measurement of the straightness of each measurement line and the calculation model of the correction error term. The Gaussian Radial basis kernel function is chosen as the kernel function of the SVR model, and the cross-validation method is used to select the appropriate model parameters to solve the convex quadratic programming problem, and then the geometric error prediction model is established. Taking the X-axis of the QLM27100–5X five-axis gantry machine as an example, the geometric error sample data is obtained by measuring and identifying based on the improved nine-line method, and then the geometric error item prediction model is established based on the support vector regression machine and the least squares method respectively, and the prediction accuracy of the two models is compared. The results show that the predictive MSE of the former is 0.0238, which is less than 0.072 of the latter. It proves that the support vector regression model has higher predictive accuracy in small sample set.

    In order to solve the problem of insufficient rigidity of the column of the disc milling column of efficient and powerful compound milling machine, the cutting force was obtained by cutting titanium alloy, the dynamic and static characteristics of the column were calculated by ABQUS finite element analysis module, and FEM is used to calculate the static and dynamic characteristics of the key structure of the column. Unit structure and frame structure are collected and optimized by variational analysis method. Several improved design schemes of the column structure are presented for the purpose of optimizing the structure’s natural frequency. BP neural network model is also put forward to find out the optimal design variable. Compared with the original one, the natural frequency of the optimized column structure increases observably. Finally, this method is applied to analyze the structure of principle prototype and the original column is optimized according to the computed results. Through machining experiments, the static and dynamic characteristics of the machine tool are improved greatly, and the correctness and feasibility of this theory are verified.

    Because of its high strength, low density, high temperature resistance and corrosion resistance, ceramic materials have a broad application prospect in aerospace field. Aiming at the limitation of traditional molding method, the digital light possessing of hydroxyapatite is studied in this paper. Using micrometer hydroxyapatite powder and photo sensitive resin, the hydroxyapatite ceramic slurry for 3D printing was prepared and the hydroxyapatite ceramic blank was formed. Based on TG–DSC thermal analysis, the degreasing process parameters of ceramic green body were determined, and hydroxyapatite ceramic samples were sintered. The surface morphology of the sample was observed by SEM. The phase composition of the sample was analyzed by X-ray diffraction and the density was measured by Archimedes drainage method. The bending strength of the sample was measured by a universal material tester. The experimental results show that hydroxyapatite ceramic samples with density of 94.9% and flexural strength of 41.3MPa can be fabricated by using digital light pocessing.

    GH710 is an important material with high strength, high temperature resistance and poor cutting performance, which make it difficult to guarantee the machining accuracy of blisk blade. According to the characteristics of GH710 blisk, CBN electroplated grinding wheel was presented. Precision grinding of GH710 blisk blade was realized based on optimization of grinding parameters and process, and verification tests were performed. The results show that the machining accuracy of GH710 blisk blade can be realized utilizing CBN electroplated grinding wheel and symmetrical plunge grinding, the profile error of blade surface is below 0.04mm and the requirement of wheel lifetime and grinding efficiency can be satisfied.

    Traditional aero-engine thermal barrier coatings (TBC) mainly focus on thermal insulation properties and reliability, and YSZ-based TBC is already well-developed technology. Yet its electrical properties under elevated temperatures is missing. On the other hand, due to the need to build sensors on turbine blade, study on electrical insulation of TBC is necessity. In this paper, the electrical properties of YSZ thermal barrier coatings at high temperature were studied, and a new YSZ spraying formula is proposed that its high temperature electrical insulation performance. Experiments show that adding a certain amount of alumina into the coating can improve the electrical insulation performance at high temperature by four orders of magnitude, and can meet the practical needs to embed MEMS sensors on the surface of turbine blades. In addition, the electrical properties of the metal/TBC/metal sandwich structure at high temperature have been analyzed by computer simulation. Sensor performance is a composite function of the electric conduction properties under high temperatures as well as size and dimensions of each layer.

    Ti–6Al–4V is suitable for a variety of additive manufacturing technologies, but the organizational evolution forms of Ti–6Al–4V manufactured by different additive technologies are different. In this work, selective laser melting with the lowest deposition efficiency and wire arc additive manufacture with the highest deposition efficiency are studied. The differences in evolutionary form of microstructures and mechanical properties of Ti–6Al–4V under these two conditions were summarized. The Ti–6Al–4V microstructure manufactured by selective laser melting is dominated by α' martensite, which reduces its ductility. The grain size of Ti–6Al–4V manufactured by wire arc additive manufacture is large and has grain boundary α, resulting in low strength. In order to solve these problems, the effective methods to improve the performance were proposed. Meanwhile, the development and future research trends of these two additive technologies were predicted.

    We have utilized the template method in our research to fabricate micro-nano structure on the surface of carbon fiber reinforced polyether-ether-ketone (CF/PEEK) for the sake of improving the anti-icing property which is meanwhile in accordance with the request of lightweight and high strength in aeronautics and astronautics area. Contact angle tester and scanning electron microscopy (SEM) are then used to measure the contact angle (CA) of water on the composite surface and analyze its topography, respectively. We can record the time for icing by the icing-delay time tester. The adhesion tester is also used to obtain the adhesive strength. Compared with the sample of no treatment, fabricating micro-nano structure could improve the hydrophobicity of CF/PEEK, and the sample replicating the topography of sand blasting & anodic oxidized metal template has the most manifest impact with the CA achieving 150.4°, prolonging the time for icing to 538s (12 times of the figure of no-treatment sample) when the mesh is 120. Finally, the relationship between the surface structure and hydrophobicity & the anti-icing property has been discussed.