• Volume 40,Issue 3,2010 Table of Contents
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    • >综述
    • Effects of Silane Coupling Agents Treated GlassFiber on Composites Interphase

      2010, 40(3).

      Abstract (1181) HTML (142) PDF 1.44 M (1890) Comment (0) Favorites

      Abstract:ased on the interphase theories of chemical bond, reversible hydrolizable bond, Interdiffusion and in
      terpenetrating network and plastic deformation layer etc. , the effects of silane coupling agents treated GF on FRP inter
      phase nanostructure and properties and FRP mechanical properties are summarized.

    • Progress in Self-Healing Polymeric Composites

      2010, 40(3).

      Abstract (1370) HTML (134) PDF 1.02 M (1893) Comment (0) Favorites

      Abstract:In this paper, the recent research progress in self-healing polymeric composites is introduced, as well
      as the self-healing mechanisms of microcapsule, hollow fibers and vascular networks self-healing models are dis
      cussed. Finally the research trends of polymeric self-healing composites are proposed.

    • Calculating Method in Thin Films Hardness

      2010, 40(3).

      Abstract (1109) HTML (200) PDF 1.23 M (1589) Comment (0) Favorites

      Abstract:To obtain the instinct hardness of the films alone from the experimental measurements, several models
      or functions exist to describe this phenomenon. Most models or functions at present are introduced compared and ana
      lyzed, their advantages and disadvantages are presented, and the future tendency of nano-indentation hardness calcu
      lation and measurement methods is presented.

    • Tin Whisker Growth in Aerospace Components

      2010, 40(3).

      Abstract (1084) HTML (158) PDF 2.35 M (1562) Comment (0) Favorites

      Abstract:The research history of tin whisker can be divided into three stages—the study of the early phenomena
      of tin whisker, growth mechanism of tin whisker and the mitigation of the growth of tin whiskers. The methods for
      measuring length and density of tin whisker are compared. The methods of mitigating growth of tin whisker are summa
      rized, including choice of different thickness of tin layer with different substrate materials, using barrier layer such as
      nickel and indium, surface reflow treatment and heat treatment of the surface finishes, avoiding a local pure tin plat
      ing, covering with conformal coat on the surface finishes.

    • >计算材料学
    • Constructing Fiber Placement Paths With Piecewise G2 Interpolation

      2010, 40(3).

      Abstract (1002) HTML (160) PDF 3.08 M (1377) Comment (0) Favorites

      Abstract:This paper presents a method for path planning of robotic fiber placement, where the initial path is
      created with curvature continuous (G2) interpolation of data points on surface with specified tangent direction and curvature vector at every point. Making use of some conclusions deduced from the isomorphic relations between tangent spaces of both surface and its parametric domain at corresponding points, we convert the problem of curve interpolation on a parametric surface to a similar one on its parametric plane. The method enables us to express G2 interpolationcurve of an arbitrary sequence of points on a parametric surface explicitly in parametric form. For introducing several free parameters into the method, we can modify the curve爷s shape locally or globally. Moreover, the resulted place
      ment path can reflect the curvature of the mould surface and change the fiber爷s direction locally so as to satisfy better the demand of both fiber placement and surface geometry. Experiments demonstrate the method is simple, feasible and also applicable to computer aided design and computer graphics, etc.

    • Research on Rectangular Packing Algorithm

      2010, 40(3).

      Abstract (1041) HTML (186) PDF 1.89 M (1551) Comment (0) Favorites

      Abstract:摇A rectangular packing algorithm based on two dimensional bin packing problem was designed. The al
      gorithm was hybridized with Genetic Algorithm to solve rectangular packing problem. In consideration of the packing height not exceeding the length of board,a new board was added to arrange the remaining components. Examples show that the presented rectangular packing algorithm is effective and reasonable.

    • Numerical Simulation and Process Optimization ofTC4 Titanium Alloy Frame Part on Hot Extrusion

      2010, 40(3).

      Abstract (936) HTML (129) PDF 1.27 M (1403) Comment (0) Favorites

      Abstract:In order to obtain forming process scheme and suitable parameters for TC4 titanium alloy frame part,
      Msc/ Superforge software was used in simulating overall hot extrusion and segment parts hot extrusion. The simulation results show that high extrusion force and difficulty in forming in overall extrusion process made it not suitable for this product,but low extrusion force in segment parts hot extrusion resulted in good shaping. This process is suitable for this product and the initial extrusion temperature 920, extrusion speed 3mm/ s is better condition for it.

    • Ant-Colony Optimization Method for Knowledge Discovery in Processing Technology

      2010, 40(3).

      Abstract (921) HTML (135) PDF 1.09 M (1427) Comment (0) Favorites

      Abstract:Processing technology is much more complex, usually large in size,and continuously changes. Aiming
      to solve a series of key technologies during the matching and reasoning of discovery,a clustering algorithm that imitates the ecosystem taking into account the features of processing technology data was presented. A method of processing knowledge discovery is implemented by using of an Ant-Colony clustering algorithm and probable query,baseed on the method,the mathematical model of processing knowledge is establised. By inputing process data,Ant-Colony algorithm can be operated,the index map can be described,the process procedure can be drawn. Finally,an instance is verified based on the process information table of the milling. The result proves that the knowledge discovery based on the Ant-Colony clustering algorithm model optimizes the process sequence comprehensively and efficiently.

    • >新材料新工艺
    • New Type of Wave Penetrating Quasi Ceramic Matrix

      2010, 40(3).

      Abstract (1097) HTML (183) PDF 1.49 M (1984) Comment (0) Favorites

      Abstract:The curing process and quasiceramic properties of vinylcontaining polysilazane ceramic precursor PSN1 were studied. TGA and DMA were employed to investigate the thermal properties. The data show the decomposition temperature and the residue weight of the quasi-ceramic matrix with the increase of quasi-ceramic temperature,580 and 87% are achieved under N2 atmosphere while above 550 and 95% are achieved under air atmosphere respectively. No obvious Tgof the 420 guasi-ceramic is observed below 400. Network vector analyzers data show the dielectric constant is below 3 and just changed slightly with the temperature and frequency. Water uptake measurement shows the quasi-ceramic matrix has low water uptake properties, with the minimum of 0.03%. All the data show the quasi-ceramic PSN1 matrix is potential to be used in wave-penetrating composites.



    • Effects of γ Ray Irradiation and Atomic Oxygen Treatment on ZnO :Al Films

      2010, 40(3).

      Abstract (1130) HTML (153) PDF 1.31 M (1510) Comment (0) Favorites

      Abstract:To study and compare the effects of γ  ray irradiation and atomic oxygen (AO) treatment on the prop-
      erties of ZnO:Al (ZAO) films, two groups of ZAO film samples were prepared by direct current magnetron sputtering. Films in the first group were irradiated by γ  ray. Films with different thicknesses in the other group were treated with AO. The microstructures, morphologies and electrical properties of ZAO films before and after the treatments were characterized by modern advanced methods. It is found that high dose of ray irradiation decreases the crystallinity of ZAO films, while irradiation with low rate has an annealing effect.γ  ray can also excite the electrons, resulting in the increase of the carrier concentration. The highest ratio of increase reaches 16. 39%. AO treatment has oxidation effects on the surface of ZAO films, leading to the increase of the content of crystal lattice oxygen. The carrier concentration is accordingly decreased and the ratio of the decrease drops as the film thickness grows.

    • Changes of SiB4 Powder During Process of Chemical Vapor Infiltration of SiC

      2010, 40(3).

      Abstract (1041) HTML (166) PDF 1.55 M (1810) Comment (0) Favorites

      Abstract:The phase composition and microstructure of SiB4 powder during the process chemical vapor infiltration (CVI) of SiC were analyzed by EDS,SEM,XRD. Thermodynamic calculation was carried out in order to investigate the changes of SiB4 powder. The results show that the SiB4 particles do not decompose during CVI SiC process,but they are oxidized to form SiO2and B2O3 near the external surface of the specimen. Therefore, the matrix of C/ SiC composite modified by SiB4 particles,by using CVI combining with slurry infiltration processes,is not homogeneous and compact. The uneven oxidation makes it difficult to study the oxidation mechanism of C/ SiC-SiB4composite.

    • Effects of Space Ionizing Radiation on Transmission of Lanthanum Glasses

      2010, 40(3).

      Abstract (1060) HTML (149) PDF 1.26 M (1579) Comment (0) Favorites

      Abstract:A study of the effects of 60Co gamma radiation on the transmission of lanthanum flint and lanthanum crownglasses was presented for application in space optics. The max total dose attained was 10 kGy, and the experimental resultsshow that the visible transmission for all samples decreases, while the nearinfrared transmission shows a slight decrease.Although the transmission of the lanthanum flint glass LaF10 is the minimum of all samples before irradiation, it also showsa minimum transmittance loss after irradiation. The total accumulated radiation doses with and without a 10 mm thick Al shielded layer are simulated for the eight orbits of different altitudes in a 10 year mission. The simulating results indicate
      that in 3 000 km, 6 000 km and 10 000 km orbit altitudes, a thicker shielded layer is required to reduce the total dose,while in the other five orbits, a 10 mm thick Al layer is enough for satisfying the optical system performance.

    • Effect of Electrochemical Treatment on Surface Characters of PAN Based Carbon Fibers

      2010, 40(3).

      Abstract (970) HTML (146) PDF 1.17 M (1492) Comment (0) Favorites

      Abstract:PAN based carbon fibers (TOTO IM6006K) were electrochemically treated in acidic and salt like electrolytic solution at different temperatures. The surface characters of the carbon fibers were characterized by SEM,XPS, adsorption of methylene blue (MB+ ) and Raman spectra. Experimental results indicated that more functional groups and deeper grooves generated on the surface of carbon fibers after electrochemical treatment. Variation of electrolytes and temperatures can affect the configuration of specific functional groups, the difference of formed amounts of hydroxyl and carboxyl groups are 61. 38% and 98. 59% at most. More acidic functional groups and roughness appeared on the surface of the carbon fibers treated in acidic electrolyte solution, and further,higher solution temperatures were helpful to improve oxidative etching on surface of carbon fibers by active oxygen. Superficial crystallite size of the treated carbon fibers decreased by 9. 75% at most.

    • Effects of Particle Size on Electromagnetic and Microwave AbsorptionProperties of Fe-Si-Al Alloy Microwave Absorbing Materials

      2010, 40(3).

      Abstract (1049) HTML (152) PDF 1.31 M (1652) Comment (0) Favorites

      Abstract:In order to clarify the relationship between particle size of absorbents and the electromagnetic,microwave absorption properties of microwave absorbing materials, gas atomized spherical Fe-Si-Al alloy powders were used as raw materials,and Fe-Si-Al alloy powders with different particle sizes were obtained through screening. Fe-Si-Al alloy microwave absorbing materials were prepared with silicone rubber as matrix. Effects of particle size on specific saturation magnetization, electromagnetic parameters and microwave absorption properties of Fe-Si-Al alloy powders and microwave absorbing materials were investigated with sample vibrating magnetometer and vector network analyzer. The results show that specific saturation magnetization of Fe-Si-Al alloy powders and complex permeability of microwave absorbing materials increase, and complex permittivity decreases with the decrease of particle size. Moreover, the matc
      hing frequency of Fe-Si-Al alloy microwave absorbing materials with thickness 3 mm shifts to low frequency with particle size decreasing. The reduction of the absorbents爷particle size can contribute to the improvements of their electromagnetic properties and microwave absorption properties in the low frequency range.

    • Effects of Heat Treatment on Tensile Properties of C/ SiC Composite

      2010, 40(3).

      Abstract (904) HTML (145) PDF 5.00 M (1431) Comment (0) Favorites

      Abstract:C/ SiC composites fabricated by isothermal chemical vapor infiltration were heat treated. Acoustic emission (AE) was introduced to analyze the variations of AE accumulative energy during monotonic tensile test. The microstructures were examined by scanning electronic microscope (SEM). The results indicate that, for the thin interlayer C/SiC, its tensile strength is close to the initial one after heat treatment at 1 500 , but tensile strengths of the compositescan be increased after heat treatment at 1 700 and 1 900. With the increase of heat treatment temperature, tensile stresses increase significantly and modulus decrease gradually. For the thick interlayer C/ SiC, tensile strengths have little changes and tensile stresses increase obviously but modulus decrease gradually after heat treatment at 1 500 and 1 700, while tensile strength and strain begin to decrease but modulus has little change after the same heat treatment at 1 900. Heat treatment remarkably improves the toughness of C/ SiC composites. The fracture work and AE accumula tive energy increase obviously after heat treatment. For the composites with thin interlayer, the fracture mechanism varies from brittle mode to toughness one, and for the composites with thick interlayer, the toughness is further enhanced.

    • Effect of Homogenizing Treatment on Microstructure of Cast TiAl Based Alloys

      2010, 40(3).

      Abstract (995) HTML (129) PDF 3.22 M (1330) Comment (0) Favorites

      Abstract:The effect of homogenizing treatment on the microstructures of two cast TiAl alloy with B addition was
      investigated. It is found that homogenizing treatment at 1 370 /5min/ OQ and 1 150 /6 h/ AC can efficiently promote the elimination of B2 phase segregation,and the solution of bstabilizing elements to the matrix results in composition homogenization. The coarse as cast lamellar microstructures can be decomposed completely and transformed into fine near gmicrostructures through the above homogenizing treatment. The average grain size of fully lamellar microstructures is about 50 mm.

    • Development and Technological Test of Micro Electrochemical Jet Machining Device

      2010, 40(3).

      Abstract (849) HTML (126) PDF 1.28 M (1396) Comment (0) Favorites

      Abstract:Micro electrochemical jet machining (EJM) possesses some unique advantages,such as high efficien
      cy and good machining surface quality. For improving the efficiency and machining quality,a special jet device was designed and manufactured,and preliminary processing experiments were performed with the device. The results show that electrolyte can be sufficiently “cathodic polarized in the cavity of the device and the stable breakup length of electrolyte stream is long enough to machine,so the device meets the requirements for processing experiments.

    • >测试分析
    • Aero Optics Testing Schemes for Infrared Radome

      2010, 40(3).

      Abstract (955) HTML (210) PDF 974.13 K (1404) Comment (0) Favorites

      Abstract:In order to explore the target recognition influence of the guidance through infrared radome under aer
      odynamic heating, the straight through and the three way test methods were studied on the arc heated facility aimed at the simulation of heating and transmitting together. Several kinds of infrared radome material were tested under some aerodynamic heating conditions, and the infrared transmission effects were obtained. Between the two schemes, the three way test method is preferred due to its adaptability and convenience.

    • Oxidation Resistance Mechanism of SiC in Arc Heater

      2010, 40(3).

      Abstract (1020) HTML (156) PDF 1.59 M (1443) Comment (0) Favorites

      Abstract:The experiment of oxidation resistance mechanism for silicon carbide in arc heater is introduced. Test
      conditions were confirmed according to active and passive oxidation mechanism of the SiC composite material. The results indicated that the silicon dioxide (SiO2) film appeared on the surface of silicon carbide when the surface temperature is less than the transition temperature;the film prevented the ablation of the materials because that decreased the reaction between oxygen and carbon materials. On the other hand,the silicon carbide surface ablated when the surface temperature is higher than the transition temperature.

    • Tensile Properties and Microstructure of TA15 Titanium AlloyParts With Local Loading

      2010, 40(3).

      Abstract (977) HTML (155) PDF 2.72 M (1262) Comment (0) Favorites

      Abstract:Tensile properties and microstructure of the first loading region, last region and transition region of TA15alloy parts with different local loading were studied by experiment. The result shows that the room and high temperature tensile properties of the first loading region and the last loading region are better than those of transition region, but the high temperature stress rupture is no different when the local loading is applied. When a refined forming is added by whole loading after local loading process, the room and high temperature tensile properties of the transition region are better than
      those of the first and the last loading region, but the high temperature stress rupture of the transition region is bad. When the local loading is applied only, the tensile properties and microstructure are better in comparison with those with local loading first and than with whole loading at last.

    • Scanning Figure Design of Electron BeamCladding Modification Technique

      2010, 40(3).

      Abstract (986) HTML (166) PDF 1.46 M (1772) Comment (0) Favorites

      Abstract:The scanning figure was designed in terms of the electron beam(EB) characteristics. Titanium alloy
      and silicate coating were fabricated by electron beam irradiation with this figure, the effect of scanning figure on energy input uniformity was studied. The temperature field uniformity of the melting point was synthetically influenced by EB scanning figure, EB quality, EB scanning frequency and EB parameter. This scanning figure was suitable for EB cladding process. EB scanning figure is a pivotal factor affecting the temperature field of the remelting surface in the process of EB modification.

    • Storage Reliability of Aluminum ElectrolyticCapacitors in Hygrothermal Environment

      2010, 40(3).

      Abstract (1136) HTML (174) PDF 1.23 M (1509) Comment (0) Favorites

      Abstract:In view of the failure problem of aluminum electrolytic capacitors in storage environment, electrolytic
      capacitors were investigated through humid heat test. The influence of hygrothermal environment on the surface state and electric performance of aluminum electrolytic capacitors was evaluated. And the failure phenomena were observed and analyzed. The results showed that corrosion of lead and molds of rubber plug occurred on aluminum electrolytic capacitors in hygrothermal environment. Temperature had great effect on the storage reliability of aluminum electrolytic capacitors. Corrosion rate of lead was accelerated when the temperature was higher than 40. The suitable temperature for molds growth was 30. No mold was found in the rubber plug when temperature was higher than 30. The capacity and leakage current of aluminum electrolytic capacitors increased with storage time, which was caused by the corrosion of aluminum oxide film on anode foil.

    • Eeffect of Substrate Preheating Temperature onTensile Strength of Thermal Barrier Coatings

      2010, 40(3).

      Abstract (978) HTML (160) PDF 0.00 Byte (1265) Comment (0) Favorites

      Abstract:ZrO2 coating was developed by plasma spraying process in different substrate preheating temperature, and the tensile test and XRD were used to investigate the influence of substrate preheating temperature on tensile strength. The highest tensile strength can be obtained when the substrate preheating temperature is 250, the highest value is 13.4 MPa.When substrate preheating temperature is higher than 350, the mass of the thermally grown oxide on bond coatings increased more and the tensile strength reduced.

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