In recent years, the technology of lattice structure has developed rapidly with the development of additive manufacturing. It has shown great potential in the application of structural and functional integration technology. It can be used as a good design carrier for multi-function, and it can realize the organic integration of various functions such as bearing,heat proof, stealth and variant. However, some key technologies have yet to be broken, and so far there has not been a large scale application of the lattice structure in the aircraft. Combined with the requirement of aircraft structure/function integration, the manufacturing technology, performance characteristics and typical applications of dot matrix structure are reviewed, and the reasons for the application of lattice structure are analyzed and discussed from the aspects of structure design, manufacturing process and performance evaluation.

The history and current status of additive manufacturing for the aerospace titanium industry is reviewed. The build efficiency, dimension capability, component complexity, buy-to-fly ratio, and surface quality of 5 additive manufacturing methods based on direct energy deposition and powder bed fusion are compared. Also, the effect of powder bed fusion technology on designing lightweight structure and low-cost manufacturing process is discussed. Taking Ti-6Al-4V as an example, how the physical processes inside melt pool affects the formation of columnar grains and mechanical anisotropy is investigated. Some results of process monitoring and quality control, as well as the current standard for material,processing, and detection are presented. Finally, the cost breakdown and model are introduced to explain the component features that are suitable for additive manufacturing. The future direction of aerospace additive manufacturing for titanium alloys is discussed.

Metal additive manufacturing (MAM) technology has been developed rapidly in aerospace, ship building,automobile manufacturing and bio-medical industries. However, MAM technology is characterised by a number of issues that are slowing its wider implementation. The peculiar microstructure of MAM components leads to anisotropy, the components are affected by residual stresses and distortion during MAM, and also it is easy to produce cracks and holes. Therefore, this paper mainly introduces several methods and techniques for improving the microstructure and performance of metal additively manufactured materials, such as optimization of process parameters, post-treatment, particles introduction,ultrasonic interference technique, ultrasonic impact treatment, rolling and ultrasonic micro-forging technique.

The paper is to prepare the refractory high entropy alloy, NbMoTaTi, in aerospace industry by laser cladding deposition technology. The crystal structure of the alloy is single phase solid solution structure of BCC analyzed by Xray diffraction. The grain size of the NbMoTaTi high entropy alloy is mostly between 2-12μm. The average micro-hardness is 397.6HV and the room temperature compression strength is 1301.83MPa. The high temperature compression strength under 1000℃ is only 347.28MPa because of the defects such as pores, without /incomplete melting Ta powder particles and cracks generated during the forming process of NbMoTaTi high entropy alloys, so further research is needed.

In this paper, the current research situations of SiC particle reinforced aluminum matrix composites manufactured by selective laser melting (SLM) at home and aborad are synthetically reviewed. And the technical difficulties of SiC particle reinforced aluminum matrix composites processed by SLM technology are also analyzed. The application cases of SiC particle reinforced aluminum matrix composites in the field of aerospace and the advantages of SLM technology are then introduced. Finally, the paper makes a prospect of the research of SiC particle reinforced aluminum matrix composites processed by SLM technology.

The laser deposited additive manufacturing is of a revolutionary significance for aircraft landing gear manufacturing.It has many technical vantages, such as breaching restriction of material specification, reducing waste of original material, and shortening manufacturing time. This technology has obvious advantage and application prospects on rapid trial-manufacture for the future aircraft undercarriage. At present, the key technologies of laser deposited A-100 steel such as forming process, quality control and so on have been breached through. The undercarriage formed by laser deposition has achieved leading application on aircraft. Mechanical properties of parts reached almost that of the forgings. Some keys such as strategy of forming process, control of heat treatment, non-destructive testing, surface strengthening and integrated evaluation, need to be further broken through and solved for extended application of this technology.

Hexagonal honeycomb were manufactured using plant fiber paper as raw material, and the mechanical properties, fire retardant and water absorption of plant fiber honeycomb were tested. The result shows that the compression property and L direction shear properties of the plant fiber honeycomb are lower than those of aramid paper honeycomb, which could fulfill the requirements of Q/6S 1015-2005; The average char length of plant fiber honeycomb is 35mm, the max smoke density in 240s is 16.2; the water absorption rates of 1.83-48 plant fiber honeycomb is 5.5%, and the retention rate of compression strength of honeycomb is 87.6%; the phenolic resin dipped into the interior of the plant paper, thus the honeycomb holes become thinner than aramid paper honeycomb, and the gum area becomes smaller, correspondingly.

A thin 3D reduced graphene oxide(rGO)/CNT/Fe3O4 composite based on carbon film with outstanding electromagnetic wave interference shielding capability was fabricated by solvothermal method and electrophoresis. Then,multi-layered composites were prepared based on epoxy resin. The influence of electric field and deposition time on the morphology of the graphene oxide nanosheet and conductivity and shielding efficiency of 3D rGO/CNT/Fe3O4/epoxy composites was analyzed. 3D rGO/CNT/Fe3O4/epoxy composite with 4-layer has a thickness of 1.4mm, and its shielding effectiveness is up to 49.7dB in the X-band frequency range. More significantly, its specific shielding effectiveness is as high as 35.5dB/mm, which surpasses the value of most of the current carbon-based composites, and its tensile strength is 52MPa. Therefore, the successful fabrication of this novel material signifies the potential of the use of graphene as a thin and highperformance EMI shielding material.

The high cycle vibration fatigue test for titanium alloy hollow structure is proposed. The critical location can be defined based on numerical analysis and experimental testing. Closed loop control of testing system is realized by using resonance resides method. The test method is validated by hollow plate specimen testing. The results show that the proposing test method can accurately determine the critical location of the structure. And the stress and amplitude conform to the linear rules under the test condition. Also, sine reside control mode can conduct the closed loop control of continuous testing. The research will bring lots of benefits, including improving the accuracy of the test on titanium hollow structure,effectively cutting the high cycle fatigue period. It is of great significance on improving the level of safety and reliability of aviation as well as aerospace vehicles.

The honeycomb sandwich structure composite material is formed by automated fiber placement technology,lateral pressure deformation of honeycomb core and prepreg fiber bridging are defects, the formation mechanism and influencing factors of them are analyzed. Design concave molding tooling for two kinds of molding process, adhesive film pre-bonding process and taws zero-tension technique have been proposed to avoid defects. Completing the laying of the flatbed honeycomb sandwich, comparing the parts after curing: its cannot avoid the prepreg fiber bridging use concave module, and bridging position appears stratified, lack of resin defect; convex module is more suitable. The results can provide the reference for forming complex honeycomb sandwich structure composite material.

Influence of geometric parameters on the stress and strain distribution and the occurrence of surface groove during superplasic forming is simulated based on a plane strain model for three-sheet titanium SPF/DB hollow truss structure.Parameter ranges satisfying superplastic forming process requirement are obtained after experimental verification, providing a basic for design of three-sheet SPF/DB hollow structure.