Abstract:The mechanism of microencapsulated self-healing polymeric materials is discussed.Recent developments of self-heal systems with increased healing efficiency are introduced as well.The research trends in this area are also proposed.

Abstract:The research progress of resin flow behavior in vacuum infusion molding process is reviewed.The flow mechanism of resin,the numerical simulation of resin flow behavior and control of the vacuum infusion molding process are discussed in detail.The study prospective of resin flow behavior in vacuum infusion molding process is proposed.

Abstract:The development of CMP technology for SiC single crystal is described.The progress and problems of CMP for SiC single crystal are reviewed in the paper,the theory of CMP for SiC single crystal and the influence of technical parameters are discussed,then the future prospect of CMP is outlined.

Abstract:Implementing digital composite structure definition was the base of achieving the data integration of design,analysis and manufacture for aircraft composite structures.Basic elements of composite integration developing environment and integration developing flow are given and several key technologies are discussed.The digital composite structure definition consists of the modeling of geometry and the modeling of material structure.The modeling process is summarized.According to the fact that the composite structures can not be analyzed today based on the final shape with true fiber orientations,the content and organization of interface data are summarized.By using automatic mapping of fiber orientation data to the finite element mesh,the automatic data transfer from design to analysis is realized.At last,the data content and integration style of design and nesting and cutting system,design and laser projection system are studied.

Abstract:Based on digital image technique,true sectional image of heterogeneous composite materials was obtained.By selecting local region of the section as individual cell for micromechanics characterization,local property field of material was acquired with the use of moving-window technique in sequence combined with improved FVDAM(finite volume direct averaging method),then local property field is used in FEM,loal stress is estimated in condition of macro-load,which presents a new way of thinking in analyzing failure of composite due to local behavior.

Abstract:A rectangular layer packing algorithm based on two-dimensional strip packing was designed.The algorithm is hybridized with simulated annealing algorithm to solve rectangular layer packing problem.The strip is divided into layers whose numbers depend on the components to be packed.Example shows that the presented rectangular packing algorithm is effective and reasonable.

Abstract:The oxidation mechanism and transition temperature of silicon nitride were studied.The results indicate that the silicon nitride burst easily at high temperature,the silicon dioxide film and the nitrogen generate under passive oxidation mechanism.The results also indicate that silicon nitride and silicon carbide have the same transition temperature.

Abstract:Temperature rising curves of Gr/Al thermal protection materials tested by oxyacetylene ablation show that Al escaped from Gr/Al thermal protection materials absorbing heat to slow down temperature-rising rate,thus realizing thermal protection effectively by evaporating and melting.Furthermore,this paper built the heat-transfer model according to heat-transfer properties of Gr/Al thermal protection materials.

Abstract:γ-Al2O3 as an additive was adopted into nano silica porous thermal insulating material to reduce the volume shrinkage at higher temperatures.The effects of sintering temperature and mass ratio on volume shrinkage were investigated,and the effect of γ-Al2O3 on thermal insulating properties was also analyzed.The results show that the volume shrinkage strongly increases with temperature,and the additive of γ-Al2O3 can significantly reduce the volume shrinkage.When the mass ratio is 5%,the volume shrinkage decreases from 10.49% to 3.47% at 1 000℃.Moreover,better result can be achieved with increase of mass ratio.Meanwhile,γ-Al2O3 has little influence on thermal conductivity at higher temperatures.Finally,the mechanism of shrinkage restraint is illuminated by the kinetics of solid sintering and characteristic methods of XRD and FESEM.

Abstract:New silicone rubber/etheylene propylene diene rubber(SiR/EPDM) blended insulation materials for solid rocket motor were prepared by mechanical blending silicone rubber with EPDM.The insulations were characterized by liner ablation test.Mechanical properties and thermal properties were studied.Ablation test show that with increasing the content of EPDM in SiR/EPDM the linear ablative ratios decreased.When SiR/EPDM is 60/40,the linear ablative ratio decreased to 0.09 mm/s due to forming a relatively tough and rigid inorganic char layers.SiR/EPDM presents higher thermal stability in comparison with EPDM and better mechanical properties in comparison with silicone rubber respectively.

Abstract:The best size of metal microwave absorbing particles was investigated.From the view point of skin depth and the critical size of single magnetic domain particle,the best size of metal absorbent is analized and numerically calculated.It is found out that for pure Fe while the size is within the range from 16 nm to 1 μm,its properties are satisfactory at 2 to 18 GHz.In order to utilize the quantum size effect of nano-particles to absorb microwave,the calculation results indicate that the size is less than 22 nm at least.

Abstract:Bonded T300/CYD128 composite repair of 1.76mm aluminum substrates was prepared by vacuum bagging technology.The hygrothermal properties of bonded composite repair of aluminum substrates were investigated,so do the composite material's pulling sample and it is epoxy casting sample.The Results show that the saturated water absorption of epoxy casting samples is 0.9%,but there is an obvious step in the water absorption dynamics curve.Along with the extending of the hygrothermal effect,the properties of composite material and its epoxy casting sample are increased at first and then decreased.The peak properties appear at 300 h(1 531 MPa) and 500 h(73.9 MPa) respectively.Along with the extending of the hygrothermal effect,the properties of cracking-aluminum substrates fall nearly linearly,the falling rate of fracture load is 0.12 kN/100 h.The properties of bonded-aluminum substrates are unstable.

Abstract:Carbon fiber(CF)/basalt fiber(BF) hybrid fibers plain fabric reinforced phenolic resin composite was synthesized.The composite laminates were tested and the interlaminate shear strength,thermal properties and ablation behaviors were studied by adjusting its resin content.The testing results indicated that the CF/BF hybrid fiber reinforced composites combined the advantages of both carbon fiber and basalt fiber.When resin content is 35%,the composite performance reach extreme value:warp and weft interlayer shear strength are 21 MPa and 20 MPa.When resin content is 39.5%,thermal conductivity and linear ablation rate are 0.366 W/(m·K) and 87 μm/s respectively.The properties of new composites has complied with the rules of hybrid effect.

Abstract:The modification of the non-linear conductivity property for polyimide by the non-linear filler was studied.The conductance property and other dielectric properties of pre and post modification and the influence of the amount of non-linear filler for conductance property of polyimide was also investigated.The experimental results indicate that the conductivity of the modified composite materials varied according to the amount of non-linear filler.When the mass fraction is less than 5%,the conductivity declined slightly,when the mass fraction is more than 5%,the conductivity went up significantly.The non-linear conductivity of modified composite materials changed obviously.

Abstract:Black oxidation film was obtained on Aluminium Alloy by two-step oxidation.The anticorrosion properties of the film were evaluated by neutral salt spray tests and electrochemical polarization curve.The morphology of the film was studied by scanning electron microscope.The composition of oxidation film was determined by EDS.This experiment result indicated that the oxidation film coatings had large lumps with lots of crackles by SEM experiments and that the oxidation film consisted of oxygen,aluminum,manganese,cobalt and chromium and that the treated Al without sealing had a lower corrosion resistance in 3.5% NaCl solution,but the samples sealed by K2Cr2O7 has a good corrosion resistance in 3.5% NaCl solution.

Abstract:The effect of laser peen and shot peen trentments on the friction stir welding(FSW) joints of 7075 aluminum alloy was investigated.The effect of these treatments on surface roughness,micro-hardness,residual stress,crack extension and fatigue life was analyzed.The test results show that the surface roughness of laser peened FSW joint is much better than that of shot peened FSW joint,the micro-hardness of FSW joints is similar for different treatments.The residual stress distribution of FSW joints can be changed by laser peen,so laser peen is an effective way to increase fatigue strength for FSW joints.The test results may serve as a reference for laser peen on some other welding joints and components.

Abstract:Trochoidal parametric equation was formulated.Based on CAM/HSM technology,Trochoidal tool path was applied to high speed milling slot experiments.Milling force,surface roughness and local surface morphology were measured,observed and studied comprehensively.An analytical milling force model was defined depending on the study of milling force.The results indicated that trochoidal tool path in high speed milling slot is effective and feasible,and a high-quality slot surface(Ra=0.142 μm) is obtained.The milling force of trochoidal tool path is varied periodically.In the milling plane,the cutting force in trochoidal width direction is quadrupled to the width of trochoidal step ahead.Introduce circumferential cutting tool path to trochoidal peripherally,not only improved the slot of milling condition,but also meet the high speed milling of rough milling and finishing requirement.

Abstract:When winding the gyration,the fiber accumulation on the gyration end will decrease the winding accuracy,cause the machine movement interference and lead to material waste due to the difference of the winding angle,transitional end length and module diameter.Aiming at the end accumulation of the gyration winding,an accumulation decreasing method is proposed based on the change of friction coefficient,adjustment of the trajectory skip steps and adjustment of the transitional end length.At last,this method is applied to the winding experiments of the aviation fuel filter to verify its correctness and feasibility.

Abstract:To improve activation properties and decrease the corrosion rates of aluminum,effects of additives H2O on electrochemical behaviors of aluminum anode(99.999%)in alkaline carbinol-ethanol organic solution were studied by using electrochemical methods.It is shown that corrosion rates of aluminum are largely depressed by 4 mol/L KOH+carbinol-ethanol(5∶5)+30%H2O solution,and corrosion inhibition percentage is 70.04%.At-1.20 V,its current density is 72.66 mA/cm2.Eocp is-1.933 V.

Abstract:On the basis of transmission/reflection method for measuring electromagnetic parameters,the limitation of the traditional transmission/reflection method in the calculation of the dielectric microwave electromagnetic parameters was analyzed.The electromagnetic parameters of air,the polyethylene wax and BaM-type ferrite were measured by using time domain gating technology.The results show that time domain gating technology can significantly improve the precision and the stability of measurement for materials.

Abstract: Network analyzer was connected with rectangular resonant cavity to build up a perturbation measurement system for electro-magnetic parameters of materials.Based on perturbation theory,the measurement equations for the complex-permittivity and permeability of small volume materials loaded into sample holders for measurement were obtained.The electro-magnetic parameters of a novel radar absorbing material,carbon foams,were measured.It shows that the εr′ and μr″ value of carbon foams increase gradually with the increase of electric conductivity,while the εr″value increases firstly and then decreases.Carbon foams are characterized by small permittivity,large electric loss and extrinsical magnetic loss.The unique electro-magnetic loss characteristics of carbon foams make it possible to be used as structural radar absorbing materials with wide absorbing bandwidth at elevated temperatures.

Abstract:To experimentally study the influence of pin's angle and diameter and pin materials on the strength and modulus of X-cor sandwich structures,the specimens of flatwise tensile test were made of the Rohacell 31 foam core and the pins with different kinds of diameter consisting of T300/FW-63 carbon/epoxy and SC-240/FW-63 glass/epoxy with pultrusion process.The results show that the efficiency of pin reinforcing flatwise tensile strength of X-cor sandwich structures increased first and then decreased as pin's angle increased and increased as pin's diameter decreased,the efficiency of pin reinforcing flatwise tensile modulus of X-cor sandwich structures decreased as pin's angle increased and decreased as pin's diameter decreased,the efficiency of pin reinforcing flatwise tensile strength of X-cor sandwich structures is keep constant with different pins materials,but the efficiency of pin reinforcing flatwise tensile modulus of X-cor sandwich structures is higher with higher modulus pins.