• Volume 45,Issue 5,2015 Table of Contents
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    • >综述
    • Progress on Ultra鄄High Temperature Ceramics

      2015, 45(5).

      Abstract (1814) HTML (237) PDF 2.02 M (2387) Comment (0) Favorites

      Abstract:

      Ultra鄄high temperature ceramics (UHTCs) are regarded as the most promising thermal protective ma鄄
      terials for the nose and leading edge of hypersonic or re鄄entry vehicles due to their stability of physical and chemical
      properties in extreme environment. The progress on UHTCs is reviewed in detail, including powder synthesis, densifi鄄
      cation and mechanical properties. Also, some problems exist in the material studies are preliminarily summarized. It
      is expected that this review will provide some guidance for stimulating further research and practical applications of the
      UHTCs.

    • Classification And Manufacturing Technology of Cylinder And Tank in Aerospace

      2015, 45(5).

      Abstract (1762) HTML (229) PDF 3.62 M (2385) Comment (0) Favorites

      Abstract:

      The pressure vessel of cylinder and tank are key components in space structural dynamic system. This
      paper summarized classification and current situation of cylinder and tank,introduced cylinder and tank manufacturing
      technology used in aerospace. The development trend of high鄄performance, light鄄quality, series cylinder and tank
      were predicted.

    • >计算材料学
    • Establishment of Coupled Governing Equations in the CarbonizationProcess of Thermoset Resins

      2015, 45(5).

      Abstract (1206) HTML (165) PDF 797.20 K (1780) Comment (0) Favorites

      Abstract:

      The carbonization of resins owns a very complicated with physically and chemically phenomenon, in鄄
      volving heat and mass transfer, stress and strain generation and pyrolysis. The transient governing equations of cou鄄
      pled thermo鄄hydro鄄mechanical process are theoretically derived based on physical conservation, namely equations for
      resins deformation, gas flow and energy conservation. Analysis of coupling interaction of the multi鄄physics are carried
      on. And some suggestions are proposed for further study.

    • >新材料新工艺
    • Investigation of Multilayer Ceramic/ Metal FrequencySelective Surface( FSS) Material

      2015, 45(5).

      Abstract (1278) HTML (191) PDF 1.79 M (2087) Comment (0) Favorites

      Abstract:

      In this work, the broadband wave鄄transparent materials were prepared via the composite of multilayer
      frequency selection surface( FSS). Meanwhile, the FSS was made with conductive metal material platinum through
      screen printing process, and porous nitride ceramic materials were used for medium support of FSS. Detailed analyses
      are made for microstructure and properties of the wave鄄transparent materials. As a result of the study, multilayer FSS
      struture shows excellent overlapping and consistent cycle; the FSS compostion is stable and acquires a dense structure
      layer with well conductive properties; also the multilayer ceramic and metallic FSS has transmittance of 95% at 9. 5 to
      18 GHz frequency.

    • Impact of Resin Content on Bending Property ofLightweight Composites for Armed Car Interior

      2015, 45(5).

      Abstract (1411) HTML (202) PDF 2.84 M (1735) Comment (0) Favorites

      Abstract:

      A 3D six鄄layer curved shallow鄄crossing linking lightweight fabric used for armed car interior was pre鄄
      pared using glass fiber with the linear density of 2 400 tex as raw material on a 3D loom modeled SGA598. The curved
      shallow鄄crossing linking composite applying in armored car interior was successfully prepared by hand composite mod鄄
      eling. The curved shallow鄄crossing linking and resin system was composed of epoxy resin and polyether amine in a
      mass ratio of 3 颐1,in the mass ratio of 2 颐1,3 颐2,1 颐1,2 颐3 and 1 颐2. Universal material testing machine modeled Instron
      3385H was employed to characterize the bending property of the composite and the effect of resin content to the ben鄄
      ding property of the composites was studied. Scanning electron microscope was employed to observe the fracture inter鄄
      faces of the composite and for further study on bending failure mechanism of the composite. the composite possesses
      excellent mechanical. Both of the bending strength and the bending modulus reach the maximum when the mass ratio
      of fabrics and resin is 1 颐1. The fragmentation of resin matrix and the extraction and breakage of fiber is the main fail鄄
      ure mode of the composite.

    • Effect of Carbon Nanotube Film Interlayer Toughening on MechanicalProperties of Carbon Fiber Reinforced Composite

      2015, 45(5).

      Abstract (1115) HTML (155) PDF 2.21 M (2350) Comment (0) Favorites

      Abstract:

      Carbon nanotube film(CNTF) / carbon fiber reinforced resin composite were fabricated via autoclave
      process with two kinds of carbon nanotube film interlayer toughening respectively. Effect of the molding process, ori鄄
      entation and planar density of the carbon nanotube film on the mechanical properties and interlaminar toughness of
      composite were investigated. The result reveals that compared to the vertical direction, when the CNTF were layed
      paralleling to the carbon fiber, the compression strength,90毅flexural strength and interlaminar shear strength of com鄄
      posite were better. The toughening effect of the composite enhanced as the planar density of the carbon nanotube film
      decrease. The interlaminar fracture toughness of composite interlayer toughened by carbon nanotube film sprayed is
      more outstanding evidently than carbon nanotube film drawed. When the planar density of the carbon nanotube ran鄄
      dom film was 0. 75 g/ m2, GIC and GIIC of composite were optimum, increased by 21% and 42%, respectively,com鄄
      pared to composite before toughening.

    • Multi鄄Scale Relationship of Pores in Carbon Cloth StitchedPreform and Deposition of Pyrocarbon

      2015, 45(5).

      Abstract (1222) HTML (169) PDF 1.83 M (1967) Comment (0) Favorites

      Abstract:

      Isothermal chemical vapor infiltration(ICVI) was used to study carbon cloth stitched preform densifi鄄
      cation process,methane was the precursor,at the temperature of 1 368 K and residence time of 1 s. Carbon cloth
      stitched preform porosity distribution under different time was characterized by mercury porosimetry, and the pyrocar鄄
      bon structure was observed by PLM. It is found that the porosity presented multipeek shape,and pyrocarbon deposition
      rate and [A / V]value showed a inverse correlation throughout the whole study process. The texture of the pyrocarbon
      had a relationship with the specific surface area. Isotropic and low textured pyrocarbon was first got at the initial of in鄄
      filtration,then high textured pyrocarbon was discovered at larger size pores like the edge of the bundle.

    • Environmental Resistance of HCFC-141b Blowing Polyurethane Plastic Foam

      2015, 45(5).

      Abstract (1258) HTML (215) PDF 792.13 K (1615) Comment (0) Favorites

      Abstract:

      In this paper, wet鄄hot cycling test, salt鄄fog test, accelerated aging test and solar radiation test were
      designed to simulate three special environments to test the performance change of HCFC-141b blowing polyurethane
      plastic foam. Compressive strength, closed cell proportion, liner expansion coefficient and thermal conductivity were
      tested before and after environment tests. The results indicate that after the three special environment tests HCFC-
      141b blowing polyurethane plastic foam have higher compressive strength and thermal conductivity, smaller liner ex鄄
      pansion coefficient and equivalent closed cell proportion. Solar radiation test on properties of foam effect maximum.
      Compressive strength of sample SD-4 increased by 32%, and obturator first increased and then decreased, linear ex鄄
      pansion coefficient decreased by 19%, the thermal conductivity increased 30%.

    • Scarf鄄Patch Repair Analysis of Foam Core Sandwich PanelWith Non鄄Penetrating Damage

      2015, 45(5).

      Abstract (1166) HTML (152) PDF 1.52 M (1729) Comment (0) Favorites

      Abstract:

      The three鄄dimensional finite element model of foam core sandwich panel with non鄄penetrating damage
      of SR20 airplane is established. The convergence of the model is analyzed and the effective mesh density is given.
      Stress analysis of the sandwich panel with non鄄penetrating damage under uniaxial and twin鄄axial tensile loading is car鄄
      ried out. The material principle direction stresses distribution of the sandwich panel with no defects and repaired panel
      are given. The uniaxial and twin鄄axial tensile strengths of the intact and repaired panel are calculated based on the
      strength criterion of maximum stress. It is shown that under uniaxial tensile loading, the initial damage mode of the re鄄
      paired panel is shear failure. The failure occurs on the motherboard which is beside the boundary of the repair area
      and about 30毅to the x symmetry axis of the panel. Under twin鄄axial tensile loading, the initial damage mode of re鄄
      paired panel is the fracture of the reinforce fiber. The failure occurs on the motherboard which is near the boundary of
      the repair area and is about 45毅to the x symmetry axis of the panel. In the ideal repair status, the strength recovery
      coefficient of the repaired panel under uniaxial tensile loading is 85. 8%, and 96. 7% for the same repaired panel un鄄
      der twin鄄axial tensile loading. The strength of the repaired sandwich panel decreases due to the stress concentration
      caused by the material discontinuity of the repair area. The strength of the repaired sandwich panel decreases with the
      increase of the number of surface patches. This happens thanks to the increase of local stiffness caused by the addi鄄
      tional surface patches.

    • Effect of Thermal Deformation Parameters on MechanicalProperties and Microstructure of AZ31

      2015, 45(5).

      Abstract (1162) HTML (157) PDF 2.48 M (1785) Comment (0) Favorites

      Abstract:

      AZ31 was as the research object based on thermal simulator Gleeble1500 under the conditions of hot
      compression experiment to obtain material stress鄄strain curve. Under different temperature and strain rate,using metal鄄
      lographic microscope analysis of metallographic observation was condensate, and comparative analysis of the micro鄄
      structure before and after compression was nerforel. At the same time the mechanical behavior of materials under dif鄄
      ferent temperature and strain rate was analyzed, its behavior belongs to the typical type of dynamic recrystallization.
      When hot compress temperature is 350益and 400益, material strength increases with the strain rate, and strain hard鄄
      ening is also increased. When the strain rate is 0. 01/ s and 0. 1/ s, with the increase of deformation temperature and
      stress of the material is gradually reduced. Compared with strain rate of 0. 01/ s,the stress with strain rate of 0. 1/ s is
      lower under different temperature

    • Oxidation Behavior of Nb-38Ti-12Al Alloy

      2015, 45(5).

      Abstract (1290) HTML (215) PDF 4.43 M (1836) Comment (0) Favorites

      Abstract:

      In this thesis, prepared Nb-38Ti-12Al alloy is processed into sheet. The thickness of sheet is 0. 50
      mm. Based on this, X鄄ray Diffraction(XRD),optical microscope(OM),scanning electron microscope(SEM)and box re鄄
      sistor鄄stove, and analytical balance are used to study the oxidation behavior of alloy. The oxidation behavior of Nb-38Ti
      -12Al at 1 200益is studied. The oxidation layer appeared layering phenomenon. The calculation of oxidation weight
      gain per unit area made it possible to draw oxidation weight gain curves. The kinetic equation of the intimal oxidation
      layer can be expressed by x1. 228 =34. 50t and x1. 480 =288. 73t,respectively,at 1 000益and 1 200益.

    • Mechanical Properties of Clinched Joint in Aluminum鄄Lithium and Titanium Alloy

      2015, 45(5).

      Abstract (1104) HTML (169) PDF 1.84 M (1856) Comment (0) Favorites

      Abstract:

      This paper is focus on the mechanical properties of similar and dissimilar clinched joints in 1420 alu鄄
      minum鄄lithium and titanium alloy sheet materials. Load鄄bearing and buffering capacity are the main standards which
      could assess quality of clinched joints. Force鄄displacement curves and energy absorption drawn from the test could get
      load鄄bearing and buffering capacity indirectly and also show that TA1-1420 joint owns great mechanical properties.
      Besides, compared with TA1-TA1 joint, TA1-1420 joint爷weight is lighter because of its lighter lower sheet. Results
      showed that TA1-1420 joint is more suitable for the part which require higher load鄄bearing and buffering capacity

    • Tensile鄄Shear Strength and Microstructure After Galvanize SteelClinched Joints Heat Treatment

      2015, 45(5).

      Abstract (1187) HTML (190) PDF 2.10 M (1559) Comment (0) Favorites

      Abstract:

      In this paper, a thermal treatment apparatus was established to take local heat treatment on zinc鄄coa鄄
      ted clinched joints. Then mechanical test was conducted on the specimens under tensile鄄shear condition, and the met鄄
      allographic specimens were prepared to observe the metallographic structure of the clinched specimens with heat treat鄄
      ment. The micro鄄hardness of metallographic specimens with heat treatment and non鄄heat treatment were also meas鄄
      ured. The results exhibited that compared with the clinched specimens with non鄄heat treatment, local heat treatment
      largened the degree of joint neck tear and the static strength increased by 16. 7%. The material structure of the
      clinched joints has changed from ferrite and pearlite to lath martensite after thermal treatment. In comparison to un鄄
      heated treatment, the micro鄄hardness of the new microstructure is increased by 12. 1%.

    • >测试分析
    • A鄄MAG Welding Bead Microstructure And Impact Fracture Analysis

      2015, 45(5).

      Abstract (1124) HTML (207) PDF 3.80 M (1682) Comment (0) Favorites

      Abstract:

      In order to solve the lack of fusion, A-MAG welding was invented, which obtained welded joints of
      high quality. The experiment results show that surface appearance of A-MAG weld, internal quality of welding joint
      and the welding operation perform very well. Experiments also show that the A-MAG welding can improve weld pene鄄
      tration, compared with MAG welding on the same heat input. The tensile property and bending strength of A-MAG
      are not reduced while impact strength is improved, especially in the HAZ. Dimples size of A-MAG welded joint frac鄄
      ture becomes finer. It is shown that the active MAG welding can improve the welding quality and weld penetration of
      weathering steel, which has the value of engineering application.

    • Fatigue Fractography of 5A06 Aluminum Alloy Under Different Stresses

      2015, 45(5).

      Abstract (1209) HTML (161) PDF 3.87 M (1893) Comment (0) Favorites

      Abstract:

      The high cycle fatigue fractography of 5A06 aluminum alloy was investigated by means of optical mi鄄
      croscopy(OM), scanning electron microscopy( SEM) and energy dispersive spectrometer( EDS). The results show
      that the fatigue cracks mainly initiate at the interface between impurities and matrix when the loading stress is near the
      fatigue limit. Multi鄄source fatigue cracks appear with the increase of the stress and the cracks originate mainly from
      the broken impurities. The crack deflection path becomes more complex, the fatigue striation increases and the fatigue
      expansion area becomes smaller with the stress increasing. The direction between adjacent grain favored slip planes
      determines the deflection of the micro鄄crack in the early stage of the fatigue crack propagation.

    • Delamination Damage Identification of Composite Based on Flexibility Curvature Matrix

      2015, 45(5).

      Abstract (1064) HTML (171) PDF 1.65 M (1569) Comment (0) Favorites

      Abstract:In this paper, the modal flexibility curvature matrix FCM of composite was used to discuss the NDT composite materials, the natural frequency of the composite beam and shift values of each node are simulated by modal analysis. The damage of composite beam is detected by calculating the modal flexibility curvature matrix. According to the beam theory we put forward a new theory based on the modal flexibility curvature matrix to detect the damage of composite plate,namely longitudinal and transverse flexibility curvature matrix. The results show that for a single de鄄 lamination, longitudinal and transverse flexibility curvature mutation rates were 3. 6310 and 5. 4078 times respecting. For multiple delamination the longitudinal and transverse flexibility curvature mutation rates were 3. 5350,5. 9028 times at the small damage location. While at the big damage location,the longitudinal and transverse flexibility curva鄄 ture mutation rates were 5. 6803,10. 0109 times. Mutation position of flexibility curvature mutation coincides with the preset position. So longitudinal and horizontal flexibility curvature can determine the location and size of composite de鄄 lamination, and relatively speaking, longitudinal flexibility curvature works better than transverse flexibility curvature in damage detection.

    • Experiment Analysis of Multi Imaging by Ultrasonic Testing ofComplex Defects in Composite Material

      2015, 45(5).

      Abstract (1274) HTML (182) PDF 3.69 M (1774) Comment (0) Favorites

      Abstract:

      The traditional ultrasonic B scan and C scan detection are unable to fully show overall perspective of
      composite defects in composites. In this paper, the specimen with an artificial prefabricated flaw was detected by im鄄
      mersion ultrasonic C scan imaging through the experimental method . Based on the principle of ultrasonic C scan the
      bottom wave amplitude imaging, through one scan , ultrasonic reflected signals were acquired in different depth posi鄄
      tion to form slice C scan imaging and slice C scan images were used for observe defects inside the material. Experi鄄
      mental results have shown that, complex defects in composite materials can be multi angle imaging and full range of
      clearly displayed by combined ultrasonic A, B, C scan imaging method with slice C scan imaging method.

    • Tool Applicability of the C/ C Composite With Low Ablation Rate

      2015, 45(5).

      Abstract (1273) HTML (186) PDF 3.23 M (1591) Comment (0) Favorites

      Abstract:

      To improve oxidation resistance, the granule of refractory metal compound is intermingled with car鄄
      bon鄄carbon composite. The change of matrix influences the mechanical property greatly. The cutting temperature in鄄
      creased slightly, which was lower than the temperature of common metal obviously. The influence of the cutting tem鄄
      perature for the tool life is minimal. However the high hardness of the granule of refractory compound caused the abra鄄
      sive increas dramatically, and the decreased of tool life. The dominant wear mechanism was abrasive wear, meanwhile
      there was different form of tool wear and tool breakage.

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