How to achieve the synchronous coordinating of dimensional and properties of high-performance and lightweight tubes has been a key issue in advanced manufacturing in many high-end industries such as aerospace. As one of preferred fabrication technologies for hard-to-deform tubes in aerospace industry, two-roller cold pilger rolling has unique advantages of large deformation, fine surface, and close dimensional tolerance since materials are incrementally subjected to triaxial compressive stress dominated local loading compared with drawing and extrusion, etc. However, the cold pilgering is a multi-stroke, non-steady, nonlinear and multi-factor coupling physical process. Unsuitable processing parameters may significantly affect both inhomogeneous deformation and texture evolution, thus easily resulting in the fluctuation of dimensions and properties of final tube product. The principle and characteristics of two-roller cold pilger rolling are firstly introduced, and then the studies on macro inhomogeneous deformation and micro texture evolution during cold pilger rolling are reviewed. The challenges on the synchronous coordinating of dimensions and properties of tubular materials during two roller cold pilger rolling are attempted to be summarized.

    The rotary ultrasonic machining (RUM) is a superior method for the high-efficiency, precise and lowdamage machining of advanced aviation materials. In the conventional RUM, an ultrasonic-frequency longitudinal vibration is utilized on the high-speed rotational tools. However, in the rotary ultrasonic elliptical machining (RUEM), a 2-D elliptical vibration is utilized instead of the conventional 1-D longitudinal vibration to further improve the performance of RUM. Since the invention of the RUEM, many relevant researches on RUEM have been carried out. The basic principles of RUEM and vibration types including longitudinal-torsional, longitudinal-bending and double bending are briefly summarized. The research advances of RUEM from equipment to process, and including both abrasive machining and cutting are presented. Furthermore, the development trends of RUEM including machining mechanism, applications on new materials, and tools with multiple degree of freedoms are prospected.

    This paper aims to promote the application of local resonance in ultrasonic-assisted machining and realize active and controllable manufacturing. From the phenomenon of local resonance in ultrasonic-assisted machining, the authors discuss its mechanism and introduce other theories based on local resonance. Simultaneously, the application of local resonance in simple and complex systems, and the non-resonant design theory applied in ultrasonic gear machining and ultrasonic-assisted grinding are discussed respectively. Then the stability of ultrasonic vibration based on local resonance theory is also discussed. Furthermore, the development trends and the noteworthy issues of local resonance are prospected on account of its advantages in order to provide reference for it development.

    For the problem of the fast tool wear and low processing efficiency for SiCf/SiC ceramic matrix composites ith dry drilling, an ultrasonic vibration assisted dry drilling processing method with the brazed drill of defined grain istribution is proposed. The brazed diamond drill with different defined grain distribution parameters is used to drill the iCf/SiC ceramic matrix composite w th the ultrasonic vibration. By the measurement of the machining holes, the influence aw of the defined grain distribution parameters on the tool life and the size of the hole accuracy are studied, and the abrasive ear characteristics at different positions of the tool are analyzed. The results show that the longer service life with the ore grins in the tool end surface. The longer and the more number of columns abrasive grain layout of the tool side, the maller changes for the pore size of the holes. The nearer the abrasive distance to the end of the tool, the more serious the brasive wear is, and the main wear is the wear platform and the macro breakage. The farther the abrasive distance to the nd of the tool, the less wear of the abrasive is.

    Megasonic has obvious advantages in overcoming the limitations of micro-electroforming process because of its low cavitation effect, high sound intensity and acoustic streaming. In this work, a bidirectional surface mount device (SMD) megasonic electrolytic bath was designed. And an integrated megasonic electroforming equipment was designed and made considering of other components of an electroforming reactor. Single directional megasonic assisted electrodeposition and bidirectional megasonic assisted electrodeposition was investigated, respectively. Besides, a traditional deposition of nickel was conducted as the control group. The results show that the planeness value (PV) of electrodeposited layer is 15.03μm without megasonic wave, and the PV of nickel electrodeposited layer is 15.36μm with single directional megasonic assisted. The bidirectional megasonic wave assisted electrodeposition has a planeness value 10.91μm, which obtained the most uniform electrodeposited layer among these three different electrodeposition conditions. Besides, bidirectional megasonic wave assisted electrodeposition can achieve better surface morphology than other conditions.

    The magnetic grinding processing technology can adaptively grind and process complex free-form surfaces because its processing tool is a flexible magnetic particle brush. In order to improve the processing efficiency of magnetic grinding, introducing ultrasonic vibration and changing the shape of the magnetic pole, the ultrasonic vibration assisted magnetic grinding system is established; the selection of magnetic field source and the basic idea of magnetic pole shape optimization design are discussed; through theoretical analysis and experimental results, introducing ultrasonic vibration excitation can increase the instantaneous grinding pressure of magnetic abrasive particles and improve the material removal rate to achieve synergistic effect. Changing the shape of the magnetic pole can introduce the rate of change of the magnetic field strength and promote the abrasive cutting edge. Self-renewal to improve surface quality. The above comprehensive effects can improve the efficiency of magnetic grinding processing and the grinding quality of the workpiece surface.

    The work aims to study the formation and stress distribution of the surface residual stress field of the arc groove of 6061-T6 aluminum alloy specimen after ultrasonic impact treatment. By means of finite element analysis software, the residual stress field distribution of the arc groove is simulated by ultrasonic impact treatment, and the effect of different technological parameters on the residual stress value on the bottom surface of the arc groove is investigated by comparing the simulation results with the orthogonal process test. The results show that the ultrasonic impact treatment has formed a residual compressive stress layer with a thickness of about 0.35mm at the bottom of the arc groove, the residual stress first increased and then decreased along the depth direction, and the maximum residual stress value can reach about -362.5MPa. The process test is basically consistent with the influence trend of various process parameters on the residual stress value of the bottom surface of the groove obtained by the finite element simulation under the same condition, the residual stress value at the bottom of the arc groove increases with the increase of tool vibration amplitude, and decreases slightly with the increase of machining gap, while the change of workpiece movement velocity has little effect on the stress value.

    Biomimetic studies have shown that the micro-textures of pits and grooves have much excellent properties such as drag reduction, noise reduction and self-cleaning. It is of great significance to realize micro-texture precision machining to improve the product performance. However, the current micro-texture machining methods have the problems of poor adaptability of the reference surface, high machining cost and long processing cycle. Therefore, taking the V-grooving as the target micro-texture, this paper presents a layered elliptical vibration assisted cutting micro-texture method, and realizes the machining of the V-grooving on the surface of the workpiece. Firstly, according to the trajectory characteristics of elliptical vibration, the morphological parameter model of V-grooving was established, and the relationship between the maximum scallop height and the cutting speed was derived. Secondly, according to the machining depth of V-grooving, designed
layered elliptical vibration assisted cutting path; Finally, the V-grooving machining experiment was carried out, and the obtained V-grooving is compared, which verified the theoretical analysis of the topography model. It shows that the layered elliptical vibration assisted cutting of the V-grooving can reduce the cutting force and inhibit the generation of burrs.

    The extraction of drilling and riveting point’s process information is the basic of off-line programming system. On the CATIA/CAA platform, the MBD digital model’s coordinates, vector, symbol, mark were extracted. For the purpose of the correction of vector’s direction, vector calibration and correction module was developed, by creating a reference line. In the end, an example of aircraft panel part was given to demonstrate the feasibility of this system. The results indicate that it can effectively extract corresponding process information from MBD model and distinguish abnormal vector and correct it.

    The effect of aging time on microstructure and mechanical properties of Ti-5Mo-5V-6Cr-3Al alloy tube prepared by cold rolled for high pressure gas cylinder was investigated in this paper. The results show that α phase size and phase content of cold rolling tube increased rapidly in 1 hours at 560℃ , and the tensile strength firstly increased and then decreased because which was affected by the size and content of α precipitates and dislocations and deformation twins, furthermore, plastic increased rapidly only owing to α phase size and phase content. Alpha precipitates grew slower and α phase content increased slower in 1- 4 hours, and the tensile strength firstly increased and then decreased because which was only affected by α phase size and phase content, meanwhile, plasticity continued to rise to the peak. Although α precipitates size and phase content most slowly increased in 4- 24 hours, but both of the tensile strength and plasticity decreased because of the coarsening α phase, in other words, over aging occurred.

    Aiming at the problems such as the frequent design changes, the lack of information process management, and the difficult to control the state of the Engineering Change Order (ECO), a framework of .NET-based aircraft design change execution process management system was proposed, and used VS2010 programming environment to develop a design change management system based on B/S architecture. The system standardized the ECO execution process, realized the closed loop control of the design change execution process and improved the efficiency of the technical state cleaning when the aircraft delivered.

    In the deep hole drilling process of TC4 titanium alloy, due to high drilling temperature and long chip removal path, the tool wear was aggravated, which affected the quality and accuracy of deep hole. In order to establish the processing parameters for deep-hole drilling of TC4 for actual production process, the gun drilling experiment of TC4 titanium alloy was carried out. The results indicated that drilling temperature was greatly affected by drilling speed, and the influence of feed rate was not significant. Deep-hole diameter and roundness increased with the increase of drilling speed, the co-axiality increased firstly and then decreased with the increase of drilling speed. Surface roughness of deep-hole increased with the increase of drilling parameters, surface quality of deep-hole was further deteriorated under large drilling parameters. Work hardening layer of each group was about 30μm, and with the increase of drilling speed, extrusion deformation of the chip was more serious. After the comprehensive analysis, drilling speed was 20m/min, feed rate was 0.08mm/r, which were the optimum processing parameters of TC4 titanium alloy deep-hole gun drilling under dry conditions.

    By analyzing the information obtained from the operators and each processing stage of the load-bearing frame made of titanium alloy for a certain type of aircraft, we optimize the machining process and NC programs of the part on the base of the factors which restrict processing efficiency. When dealing with the process of machining the fillets of the part, we get the plunge milling method with numbers of tests, which solves the problem of breakage of the milling cutter. By the use of indexable end milling cutter, we get the recipe for the trouble of fracture of cutting tools by the reason of uneven allowance when machining the reference surface and improve the efficiency at the same time. All of these will offer valuable experience for the machining process of similar parts.