• Volume 41,Issue 5,2011 Table of Contents
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    • >综述
    • Nitride Ceramic Materials Prepared by Urea Route

      2011, 41(5).

      Abstract (1635) HTML (312) PDF 830.15 K (3361) Comment (0) Favorites

      Abstract:The recent progress of the nitride ceramic materials including the powders,coatings,nanotubes and
      ceramic matrix composites is reviewed in detail,and the development of such materials is also discussed.

    • Development of Composites of Carbon Foam/Phase Change Materials

      2011, 41(5).

      Abstract (1446) HTML (267) PDF 2.03 M (2738) Comment (0) Favorites

      Abstract:Recent development of the composites of carbon foam/ phase change material used in thermal management system (TMS) are described. There are kinds of materials including the TMS with carbon foam/ paraffin composite, TMS with carbon foam/lithium nitrate composite and integrated vapor chamber thermal energy storage(VCTES)system. The applications of the composites of carbon foam/ phase change material were introduced.

    • >计算材料学
    • Cure Kinetics and TTTDiagram of Phenolic Resin Utilized in Resin Film Infusion

      2011, 41(5).

      Abstract (1334) HTML (197) PDF 2.22 M (3294) Comment (0) Favorites

      Abstract:The aim of this work is to prepare an novel phenolic resin(PF)film suitable for RFI process and gen鄄
      erate its TTT cure diagram. Dynamic DSC technique was conducted to establish curing kinetic model that was used to describe the relationship of curing degree time temperature and of curing degree鄄glass鄄transition temperature on isothermal conditions. Establishing the relationship between the glass鄄transition temperature and curing degree allowed the determination of the vitrification lines of the resol resins. In addition, a gelation disk experiment was employed to study the gelation of resol resins. The degree of cure at gelation was found around 53. 33%. Based on the above results
      timetemperature transition diagram was presented.

    • Determination Methods for Material and Design Allowables ofComposite Aircraft Structure

      2011, 41(5).

      Abstract (2059) HTML (304) PDF 762.15 K (3206) Comment (0) Favorites

      Abstract:In this paper, the domestic and foreign determining methods of composite structure material and design allowable values are analyzed. Through the research, the characterization and application of material allowables, examining and statistical analysis methods of test data, and the determining methods for design values of static strength, fatigue strength, damage tolerance and repair are described.

    • Analytical Modeling and Simulation of Roll Bending Process

      2011, 41(5).

      Abstract (1294) HTML (267) PDF 1.07 M (2961) Comment (0) Favorites

      Abstract:An analytical model is developed through elastic plastic mechanics, considering strain鄄hardening of
      material, and the formulas of stress,strain,residual stress,springback are given. Based on nonlinear FEM package,the dynamic simulation of roll bending is also carried out. Then stress state, plastic strain distribution, residual stress and springback are analyzed,together with effect of displacement of toproller and multi pass. The result shows that curva ture near the start point is not uniform, but curvature of the middle section of the plate is very uniform if the rolling time is long enough;the radius of bended plate is a power function of displacement of toproller;multi pass can reduce
      the fluctuation of curvature,the maximum stress and strain of the plate in bending. Finally,the analytical model and FE model are verified by experiments.

    • FEM Numerical Simulation of Spinning Processing for Al-Mg-Sc Alloy Cabin

      2011, 41(5).

      Abstract (1221) HTML (242) PDF 1.14 M (2637) Comment (0) Favorites

      Abstract:The spinning process for Al-Mg-Sc alloy cylinder with the inner circumferential rib is simulated by
      the means of FEM numerical simulation, the stress strain status of the raw material and influence of technological parameter on spinning are analyzed. The results show the material is extended in axial direction and compressed in radial direction,and the material in the inner surface is extended in axial direction. Deformation ratio and feed ratio can influence spinning process, deformation ratio ought to be small than 50% and feed ratio ought to be between 05 and 20 mm/ r.

    • >新材料新工艺
    • Preparation and Properties of PVC Flame Retardant Phenolic Fibers

      2011, 41(5).

      Abstract (1276) HTML (278) PDF 1.47 M (2891) Comment (0) Favorites

      Abstract:Phenolic fibers modified by PVC (Polyvinyl Chloride) have been prepared by melt spinning. SEM (Scanning
      Electron Microscope), DMA (Dynamic Mechanical Analysis), TG (Thermogravimetric Analysis) and FT-IR (Fourier Trans form Infrared Spectrometer) were employed to characterize the structure and performance of the PVC flame retardant phenolic fibers. In comparison the PVC flame retardant phenolic fibers with the pure phenolic fibers, the addition of 0.5wt% PVC in the precursor resin obviously increases mechanical strength and flame resistance of the resultant fibers. The tensile strength increa ses from123.0 MPa to 150.0 MPa, and the limited oxygen index increases from32.1% to 38.5%. However, the thermal stabil ity of the PVC flame retardant phenolic fibers is reduced. In addition, the carbon yield of the PVC flame retardant phenolic fibers decreases from 87.4% to 70.9% at 600益, from 62.8% to 59.7% at 1 000 in nitrogen.

    • Transformation of Molecular Structure During Foaming of PMI Foam

      2011, 41(5).

      Abstract (1810) HTML (268) PDF 1.19 M (3490) Comment (0) Favorites

      Abstract:Polymethacrylimide (PMI) foam was obtained by two steps:(1)a expandable tablet was prepared via
      bulk copolymerization of monomers mixture;(2)polymethacrylimide (PMI) foam was produced by heating the expandable tablet at 190 for 1 hour. Fourier transform infrared (FTIR),1 H-NMR,dynamic mechanical thermal analyses (DMTA) and differential scanning calorimetry(DSC) was used to investigate the effects of thermal treatment in copol ymer structures, meanwhile,the molecule structure transformation during foaming process was studied. The results in dicate that some adjacent AN and MAA monomeric units transformed into six membered imide ring structures and some of the adjacent MAA monomeric units changed into six membered anhydride ring structures,furthermore,some imide ring structure is formed due to the reaction between NH3(the decomposition products of blowing agents) and an hydride ring structures;insolubility of after heated copolymer suggested crosslinking structure is generated;the peak at  10. 50 in 1H-NMR spectrum is related to imide ring (—CO—NH—CO—) proton. Scanning electron microscope (SEM) image shows a closed cell foam with fine cell structures is obtained.

    • Design of Polyimide of Composite Materials for Radiation Protection

      2011, 41(5).

      Abstract (1395) HTML (286) PDF 968.43 K (2936) Comment (0) Favorites

      Abstract:Polyimide composite was made by using polyimide,zirconia,as raw materials and these composite were studied by X-ray diffraction analysis & UV. The results show that polyimide/ zirconia + lead has better X-ray protection performance than the pure polyimide,and its heat resistance is also very good.

    • Mode I Fracture Toughness Optimizing on T800/5228A Composite Laninate

      2011, 41(5).

      Abstract (1496) HTML (325) PDF 3.15 M (2592) Comment (0) Favorites

      Abstract:Reaction induced phase separation takes place in 5228A/ PAEK compound cure process, and cured
      phase microstructure experiences sea isaland cocontinue phase separation transition accompany PAEK content arising.Further DMA test shows that PAEK induced lowers glass transition temperature of neat 5228A matrix resin in some degree, but does not change its applied temperature. Mode I fracture tougheness shows that the spread route of crack of toughened T800/5228A composite laminate presents wave like characterization, differring from smoothly stright feature for original composite,since phase separation microstructure in toughened composite enforces crack lip unceasingly adjusting orientation in PAEK phase of high tougheness when confronting 5228A microstructure ball, therefore mode 玉
      fracture tougheness ascends greatly.

    • Advanced Pultrusion Curing Process of Cf / E Prepreg

      2011, 41(5).

      Abstract (1827) HTML (400) PDF 2.00 M (3356) Comment (0) Favorites

      Abstract:To explore prepreg curing process which adjust to advanced pultrusion technology, curing exothermic
      process of carbon fiber/ epoxy prepreg was studied in this work with differential scanning calorimetry ( DSC) to improve the typical curing process of prepreg USN12500. Then the process schemes were designed and conducted with pressure values and the time to apply pressures as variables. Based on the available equipments in the laboratory, the curing process of prepreg adopt with advanced pultrusion was simulated and samples were prepared. With void content as investigation index we optimized the curing process parameters of advanced pultrusion. The results of the test indicate that final process scheme was optimized with pretreating the prepreg at 110 for 20 min, then curing at 130 for 15 min under pressure of 0. 4 MPa, and finally postcuring at 150 for 1. 5 h. The test verificated that void content less than 1. 1% in composites profiles can be prepared.

    • Design and Application of Lightning Protection Layerof Airplane Composite Materials

      2011, 41(5).

      Abstract (1743) HTML (371) PDF 0.00 Byte (2435) Comment (0) Favorites

      Abstract:In this paper, conductive layer was made on the surface of composite ply, such as flame spraying aluminum coating, expanded aluminum foil, aluminum foil. The preparation process, the analysis of electrical resistance as well as the applicability on the large airplane were investigated and analysed in detail. The results show that,the above three lightning protection layer significantly improved the conductivity of the composite materials and has the very good applicability.

    • Preparation and Oxidation Resistance ofSiC/ SiO2 Coating for C/ C Composites

      2011, 41(5).

      Abstract (1528) HTML (249) PDF 4.07 M (2610) Comment (0) Favorites

      Abstract:In order to improve the oxidation resistance of the C/ C composites, a SiC/ SiO2 coating was prepared
      by pack cementation and low pressure CVD. The microstructures of the multilayer coating were studied by XRD, SEM and EDS analyses, and then the oxidation resistance of the as coated C/ C composites was evaluated in ambient air at 1 273 K and 1 773 K. The results show that the SiC coating prepared by pack cementation has a compositional gradient. And the external amorphous SiO2 coating prepared by low-pressure CVD effectively seals the cracks and holes of the internal SiC coating. Furthermore, the problem that an integral SiO2 film can not be formed by the oxidation of SiC coating at medium temperature (1 073 to 1 473 K) also is solved. After oxidation in ambient air at 1 273 K and 1 773
      K for 10 h, the mass losses of the ascoated C/ C composites are only 4. 97 mg/ cm2 and 0. 36 mg/ cm2, respectively.The SiC/ SiO2 coating shows excellent anti-oxidation property.

    • Performance of High Heat Flux Resistant and Anti-Electrostatic Coating

      2011, 41(5).

      Abstract (1531) HTML (299) PDF 1.37 M (2519) Comment (0) Favorites

      Abstract:A high heat flux resistant and anti-electrostatic coating was developed. The high鄄heat鄄flux resistant and anti-electrostatic performance was studied. The coating shows good adhesion to the substrate material without bubbling and peeling phenomena after exposuring to 1.5,2.5,3.6 and 7.2 MW/ m2 heat flux. The volume resistivity of the coating before and after washing are both 107 ·cm. The coating also shows excellent environment durable performance.

    • Preparation and Properties of Hydrophobic Coating

      2011, 41(5).

      Abstract (1471) HTML (341) PDF 1.01 M (3073) Comment (0) Favorites

      Abstract:Hydrophobic effect of coating depends not only on its own surface energy, but also the surface rough
      ness. The hydrophobic coating was prepared by adding hydrophobic additives to the coating to reduce the surface energy, and controlling spraying process to improve the surface roughness. The effects of types and amounts of hydrophobic additive and surface roughness to hydrophobic property of coating were studied. The results show that the contact angle can reach 139 with good hydrophobic effect when the amount of hydrophobic additive is 5%, and the coating has slightly rough surface.

    • Effect of Strain on Microstructure Evolution of PH13-8MoSteel Deformed at 1 050 to 1 150

      2011, 41(5).

      Abstract (1520) HTML (254) PDF 6.91 M (2418) Comment (0) Favorites

      Abstract:The influence of strain on deformation microstructure evolution of PH13-8Mo steel was investigated
      through isothermal compression tests using Gleeble thermal mechanical simulator within the temperature range of 1 050 to 1 150 and with the strain rate of 10/ s. The results show that dynamic recrystallization occurs partially when the strain reaches maximum 0. 69 at 1 050. However, at 1 100 and 1 150, full dynamic recrystallization has occurred when the strain reaches 0. 29 and 0. 24, respectively. The fraction of recrystallization increases with increasing strain and deformation temperature. The recrystallized grain size and average grain size of the impacted steel markedly reduce with the strain before the strain reaches 0. 29, then slowly reduce. However, the recrystallized grain size and average grain size of the impacted steel both increase with increasing deformation temperature.

    • >测试分析
    • Temperature Dependence of Specific Heat Capacity of Solid Materials

      2011, 41(5).

      Abstract (2462) HTML (337) PDF 1.23 M (10659) Comment (0) Favorites

      Abstract:Based on the analysis of specific heat capacity of different solid materials, the relationship between
      specific heat capacity of solid materials and temperature is studied and the model is built. As the example of Mo,Al2O3,graphite,W,Si3N4 and SiC, the model on specific heat capacity with temperature has been verified. The results indicate that the relative deviation between calculated and standard data is not exceeding 2%.

    • Experimental Validation of Calculated Model on Mass Loss Rate of Composites

      2011, 41(5).

      Abstract (1184) HTML (189) PDF 749.47 K (2761) Comment (0) Favorites

      Abstract:In this paper, the important characteristic parameter, namely the mass loss rate, was obtained by the
      investigating on CF/ S-157PF composite under oxyacetylene flame test conditions. And using multiple linear regression, the mathematic model on the mass loss rate and the two major factors, namely the heat flux density and ablation time is as follows: M = 0. 043·q0. 128·t-0. 191 . It is verified that, the regression model is very applicable and the fore cast accuracy is much better. So the erosion properties of CF/ S-157PF composite can be evaluated with this rapid, effective and accurate method in the oxyacetylene flame test.

    • Dependent of Shear Modulus of Elastomer on Different Pressure

      2011, 41(5).

      Abstract (1618) HTML (283) PDF 1.20 M (2555) Comment (0) Favorites

      Abstract:Planar and uniaxial tests were implemented to achieve 3nd order 5th item strain model constant of the
      elastomer and it is proved this model was superior to others. In order to measure the shear modulus of the elastomer at different pressure,that biaxial device and three board sample,were designed and the shear compression test was conducted this process was simulated. The test results show that the shear modulus of the elastomer will not decrease with enhancing compression which agreed with well with the simulation.

    • Quantitative Measurement for Disbanding Defect Using Shearography

      2011, 41(5).

      Abstract (1393) HTML (289) PDF 1.88 M (3193) Comment (0) Favorites

      Abstract:The disbanding defect is prone to be produced during adhesive bonding process. The integrality,
      strength and rigidity of product would be broken by disbanding. Investigating the capability of quantitative measurement and accuracy of shearography method is more impotent to ensure the product quality and testing efficiency. This paper presents the test principle of shearography, the characteristic acceptance specification of disbanding defect. The detecting sensitivity and accuracy of quantitative measurement is investigated when sheargoraphy method is used for inspecting disbanding on honeycomb structures. The quantitative measurement result shows that the measurement result is equal to the trim size and the accuracy is less than 10%. The shearography method could be used for inspecting the
      honeycomb structure products.

    • Calculation and Verification for Effects of Heat Loss of FlashMethod Based on Parameter Estimation

      2011, 41(5).

      Abstract (1279) HTML (261) PDF 1.09 M (2562) Comment (0) Favorites

      Abstract:Theory of parameter estimation for flash method of determining thermal properties is described,and
      simplified on the basis of sensitivity coefficients and physical significance of the parameters in the paper. By MATLAB software,the effect of heat loss on rear temperature rise is investigated, simplex search is carried out to estimate parameters with testing data, and the thermal diffusivity is obtained.

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