Mirco ultrasonic machining is an unique non-traditional manufacturing process because it can produce micro/precision components and parts made of high temperature-resistant, wear-resistant, hard and brittle materials, for instance, semiconductors, optical glass and engineering ceramics. This review mainly focuses on the current research work related to material removal mechanism, processing techniques and enabling technologies in China and abroad, and the trend of this technology as well.

With wave equation of electromagnetic wave and motion equation of electron in magnetized plasma, the dispersion equation of propagation of electromagnetic wave is obtained, through which the refractive index and inversebremsstrahlung absorption coefficient of magnetized plasma are derived. It can be found that the cut-off wavelength ofplasma decreases obviously as the intensity of external magnetic field increases, resulting in the low frequency electromagneticwave cannot pass through the plasma. For electromagnetic waves with around 1μm wavelength, the refractive indexand inverse bremsstrahlung absorption coefficient of plasma barely change with the intensity of external magnetic field. Forelectro-magnetic waves with around 10μm wavelength, the refractive index of plasma decreases as the intensity of externalmagnetic field increases, while the inverse bremsstrahlung absorption coefficient of plasma increases with the rise of intensityof external magnetic field. The theoretical analysis and numerical results reveal the mechanism of electromagneticwave propagation in magnetized plasma, which has theoretical significance in study of effect of external magnetic field andplasma on laser propagation in laser hybrid welding process.

The adhesive bonding pretreatment is an important process in the bonding of aerospace composites. The bonding strength of the adhesive bonding interface will directly be affected by adhesive bonding surface properties after pretreatment. Based on the 50kHz infrared pulse laser processing of carbon fiber reinforced resin-based composites, the effects of laser power and scanning speed on the surface morphology of carbon fiber reinforced plastics are investigated by analyzing the laser cleaning microtopographies under different parameters. The results show that the laser output power is 25.9W and the scanning speed is 9000mm/s, with the surface resin completely removed and the carbon fibers not being burned.

Laser peen forming (LPF) for large panel is a kind of deformation technology by inducing nonuniform plastic strain on surface using the laser-induced shock wave. The depth of plastic strain of LPF is five to ten times of the traditionalshot peening, hence it can be applied for the manufacture of large panel with high ribs and complex geometry. Thispaper presents a recent progress of LPF from following aspect: the mechanism of bending deformation of LPF, the shapecontrolling of LPF for complex geometry and the apparatuses developed for LPF. The background and research status quoare summarized, and the advises are given for the research of LPF. The most important for LPF of large panel is acquaintingthe bending mechanism and the process optimization and developing apparatus for LPF.

The welding test of 2060 aluminum alloy with a thickness of 2mm was carried out by laser deep penetration welding and the numerical simulation of flow field morphology was researched. The heat flow coupling model of the welded structure was established and the relevant experimental verification was conducted. Based on the heat flow couplin model, the simulation of the flow field under different process parameters was analyzed. Based on the simulation results, the effects of different laser power and welding speed on the morphology of molten pool were analyzed. The results show that the laser power, welding speed and other parameters have a significant impact on the pool key.

Carbon fiber reinforced plastics has been widely used in the aircraft industry and automobile industry owing，to its superior properties. In this paper, a picosecond pulsed system emitting at 355nm has been used for carbon fiber，reinforced plastics milling experiments to determine optimum milling conditions. The influence on milling quality and milling，depth of milling parameters including laser power, milling speed and hatch distance were analyzed. Microstructure and milling quality were discussed through the machined surface observed with scanning electron microscope. It was found that，hatch distance has a great influence on heat affected zones. A removal technique based on the experiment with different focal，planes was proposed and the depths were measured with the three dimensional profilometer. The relationship between laser energy and milling depths was analyzed and the optimal focal scheme was determined.

Concerning the communication obstacles of the working laser tracker in the field of large-scale precision measurement, combining the unique advantages of the smart glasses, a method of mobile controlling the laser tracker，with smart glasses was proposed and a laser tracker mobile measurement system based on smart glasses was designed and，implemented. Firstly, the framework of this system is multi-client server. The mobile terminal in the smart glasses and the laser tracker system were connected to the server with the TCP/IP protocol. Secondly, an effective network module was established in order to communicate with the mobile terminal, the server and the laser tracker system by using multi-threading，technology. After that, the measurement process was divided into independent measure tasks so as to improve the working efficiency. Finally, semantics definition in the measurement process and speech recognition module were achieved to ease，the difficulty of smart glasses application, free the hands of wearer and improve the intelligence level of laser tracker measurement.

Selective Laser Melting (SLM) is an additive manufacturing technology that is based on melting layers of metal powder using powerful laser without traditional limits. Considering efficiency, cost and stability, some specific rules should be complied with in process of the structure design. In this article, SLM specialty of the aero aluminum alloy support was analyzed including total time, expenditure, difficulty in post-process and stability. Then the original structure was redesigned combined with SLM specialty. Complex of the structure was studied involving performance and SLM manufacturing.An optimal structure was obtained that the weight reduced by 24.5%, weighting stiffness increased by 38.3%, displacement reduced by 32.7% at most. Total time evaluated reduced by 38.6%, material consumption reduced by 65.6% dramatically at scale coefficient of 0.5. There were no supports inside the optimal structure, the post-process was easier, and fabricating stability was significantly improved.

For the NC milling of aircraft girder parts, a plan for flexible, fast and multi-station clamping fixture is proposed. The mechanism composition, working principle and PLC control system of the flexible system are discussed in detail. Using the support plate and the baffle for positioning and pneumatic boosting mechanism is used to clamp. Sensor sensing, automatic positioning and clamping of workpiece is implemented by utilizing PLC controller. The corresponding control program is worked out and debugging success. The reference is provided for the application of multi-station flexible fixture system of aircraft structural parts in NC machining.

In this paper, the narrow flanging skin composite part was studied and the technology of autoclave was adopted. According to analyzing the structure of the part, the result shows that selecting the Invar male frame tool to layup and curing the composite part, residual stress can be reduced because of the thermal capacity during the curing process as well as the deforming of the part. During the curing process, resin can sufficiently flow and soak so as to achieve the index of porosity. The porosity of the composite component is less than 1.5%. Based on the shape of the component, the result shows that designing the aid tool for layup and compaction, identifying the direction and technique of ply during layup, the outline of the flanging and the profile tolerance and the R shape can be guaranteed. Using the technology of the temperature compensation, we explore the effect of heating rate on the mechanical properties and resin content of the skin. The result shows that the best temperature rate is 0.5-1.5℃ /min before the glass-transition temperature (T g) of the prepreg, after T g until holding time the rate is 1.5-2.2℃ /min.

Large civil aircraft has a feature of dispersed production base and high assembly quality requirements, the problem that uncoordinated assembly occurs in the process of join-assembly will result in the delivery extension and higher costs. The reasonable crafts technology and repair ability of the parts with problems are the key points of ensuring the final assembly quality. We combine the virtual assembly technology and digital measurement technology, collect the actual shape and size data of key features of different fuselage segment assembly, achieve the purpose of virtual assembly by fitting the different fuselage segment measurement data into one same fuselage coordinate system, calculate the gap, adjacent difference,angle and other GD & T parameter with the result of virtual assembly, evaluate the assembly quality and provide solution and repair amount for the existing issues of the evaluation results. Firstly, we propose the technology of the fuselage segments virtual assembly based on measurement data, secondly research the key points of the technology and use it in one aircraft fuselage join-assembly process. The application of this technology reduces the failure rates and improves the final join-assembly speed, which gets one good effect.

In order to investigate the service performance of novel fiber metal laminates (NFMLs) used in aircraft skin structure, the mechanical properties of NFMLs within -55-120℃ were studied. The interlaminar performance was evaluated by the method of floating roller peeling and interlaminar shear test. The static properties were evaluated by tensile, bend and interlaminar shear tests. The yield strength of NFMLs at high and low temperature was calculated and analyzed based on the mixing theory. The results showed that the interlaminar performance of NFMLs decreased with the increase of temperature, and the tensile or bending strength had excellent high and low temperature performance, but the stiffness decreased obviously, and the change of yield strength was different from that of pure aluminum alloy. Results indicated that the mechanical properties of NFMLs maintained well within -55-70℃ but deteriorated at 120℃ .

Corrosion fatigue is a necessary stage for the high strength aluminum alloy of aircraft in service, and it is the key to assess the life and reliability of aircraft structure. The development process of high strength aluminum alloy of aircraft was briefly introduced here. Meanwhile the important factor and key technology on environment simulation for corrosion fatigue were analyzed. The corrosion fatigue crack initiation mechanism model and extension mechanism model of high strength aluminum alloy were summarized. The difficult and emphatic point on corrosion fatigue in future research was pointed out scientifically. This is the basis for corrosion fatigue of high strength aluminum alloy to carry out the test, explore the mechanism and apply on engineering.

With the increase of new product manufacture order of aviation steering gear, multi-project resource conflict has become the serious problem of production order delivery. Based on the analysis of the characteristics of new product manufacture processing of aviation steering gear and the resource conflict, this article uses the method of Pert plan review method for reference, builds digestion model aiming to deal with new product manufacture resource conflict problem of aviation steering gear, tries to identify resource conflicts before they happen, after classifying resource conflict then deals with them, in order to achieve using the multi-project management thoughts to reasonably achieve the production scheduling goal. Finally, through the production instance, this paper verifies the rationality and validity of the resource conflict digestion model.