ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • permeation  (2)
  • Dynamic properties  (1)
  • Nickel coated graphite  (1)
  • 1
    ISSN: 1573-4897
    Keywords: MMC ; Nickel coated graphite ; Squeeze casting ; Instable interface ; Electroplating
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Metal Matrix Composites (MMC's) reinforced with continuous fibers were generally fabricated by a foil-sandwich technique or by liquid metal infiltration. Liquid metal infiltration may be used to cast final shapes in molds containing fiber preforms. It is also used to make composite wire from which may be fabricated panels and shapes by hot-press diffusion bonding or pultrusion. The major drawback of this method is that the molten matrix must wet the fiber for successful infiltration to occur, requiring special fiber surface treatments or matrix additives, and that, molten metals generally dissolve or degrade the fibers, necessitating a barrier coating on the fibers. All these problems can be solved using carbon fibers coated with metallic layers, e.g. nickel. This work analyses an easy method to produce modified carbon fibers by electroplating and the process of its recristallization. The topography of the growth front of the deposit has been studied. At temperatures higher than about 300° C an annealing under vacuum is required, because of the high reactivity of metal coating, nevertheless the heat treatment of metal deposit produces always an embrittled material.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 0887-6266
    Keywords: ionomer ; permeation ; diffusion ; sorption ; gas ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Transport properties of several gases in two ethylene-acrylic acid ionomers characterized by a different amount of acrylic acid groups and percentage of neutralization have been investigated. Sorption and permeation experiments have been performed with N2, O2, CO2, CH4, C2 H6, and SF6 in the 25-65°C range and with C3H8 only at 25°C. Gas permeabilities, diffusivities, and solubilities were evaluated along with activation energies and heats of solution. Data obtained in the present investigation were compared to analogous results reported in literature for polyethylene to better highlight the effect of ionic aggregates on the gas transport mechanism. © 1995 John Wiley & Sons, Inc.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Bognor Regis [u.a.] : Wiley-Blackwell
    ISSN: 0887-6266
    Keywords: polyketone terpolymer ; water vapor ; permeation ; clustering ; sorption ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Water transport in a polyketone terpolymer was analyzed performing both sorption and permeation experiments. Water vapor sorption tests were conducted at four temperatures (35, 45, 55, and 65°C) and at several activities. The analysis of sorption isotherms revealed the occurrence of water clustering. A reduction of the endothermicity of mixing as the amount of sorbed water increased was observed which is consistent with significant association of penetrant molecules in the polymer. Permeation experiments performed at 35°C at upstream pressures ranging from 4 to 25 Torr showed evidence of a reduction in water diffusivity as function of sorbed water concentration which is a typical indication of penetrant aggregation. © 1995 John Wiley & Sons, Inc.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    ISSN: 1435-1528
    Keywords: Dynamic properties ; time-temperature superposition ; cure-viscosity ; epoxy resin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Abstract The change of the viscosity profile during the isothermal cure of a commercially available epoxy system commonly used as a matrix for high performance composites, TGDDM-DDS from CIBA, has been obtained by means of both a constant shear rate viscometer and a dynamic one. The range of temperature investigated varied from 120 up to 180°C. The increase of the molecular weight during the cure reaction is reflected on a macroscopic level in a progressive linear increase of the logarithm of the shear viscosity up to a critical point, near gelation, where an upturn is observed. The values of the time and viscosity at the critical point have been used to normalize the experimental data in a single generalized curve of the cure-viscosity profile. The William, Landel and Ferry equation has been found to adequately describe the temperature dependence of the viscosity for systems in the range of temperatures where the cure reaction did not occur. The apparent activation energy of the cure reaction, 19.7 Kcal/mole, obtained from the critical times, is consistent with calorimetric determinations.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...