Advanced Engineering Materials

Cover image for Advanced Engineering Materials

October, 2004

Volume 6, Issue 10

Pages 793–847

    1. Multifunctional Carbon Nanotube Composite Fibers (pages 801–804)

      E. Muñoz, A.B. Dalton, S. Collins, M. Kozlov, J. Razal, J.N. Coleman, B.G. Kim, V.H. Ebron, M. Selvidge, J.P. Ferraris and R.H. Baughman

      Version of Record online: 3 NOV 2004 | DOI: 10.1002/adem.200400092

      Continuous carbon nanotube composite fibers having record energy-to-break (toughness) are reported. These fibers have been employed in the fabrication of lightweight fiber supercapacitors, which can be woven or sewn into fabrics and, therefore, be potentially considered as components for electronic textiles. Moreover, these fibers provided remarkable electromechanical actuator capabilities.

    2. Characterization of Nanocarbons Produced by CVD of Ethylene in Alumina or Alumino-Silicate Matrices (pages 804–811)

      P. Ciambelli, D. Sannino, M. Sarno and J.B. Nagy

      Version of Record online: 3 NOV 2004 | DOI: 10.1002/adem.200400090

      Alumina and alumino-silicate matrices have been used to produce nanocarbons by ethylene CVD. Bundles of aligned, opened multi wall carbon nanotubes were obtained with alumina membrane (see Figure), while with beta zeolite ultra high porosity carbon (BET surface area >2000 m2/g) was formed.

    3. Ultra Fine Microstructure in WC-Co Cermet (pages 811–814)

      S. Lay, M. Loubradou and P. Donnadieu

      Version of Record online: 3 NOV 2004 | DOI: 10.1002/adem.200400084

      Grain growth inhibitors like VC are added to WC-Co cermets to avoid abnormal grain growth during sintering. Though the effect of vanadium is known for a long time, the controlling mechanism remains to understand. Microstructural investigations carried out on industrial samples have permitted to locate precisely the inhibitor after sintering. These results are discussed in connection with WC grain growth mechanism.

    4. On the Core Localization of Grain Boundary Extrinsic Dislocations in Nickel (pages 814–818)

      B. Décamps, L. Priester and J. Thibault

      Version of Record online: 3 NOV 2004 | DOI: 10.1002/adem.200400086

      Grain boundaries (GBs) have a significant influence on mechanical properties of single-phase materials. During deformation, matrix dislocations interact with GBs that constitute very strong barriers to dislocation glide processes. Some dislocations may enter the GB, giving rise to extrinsic grain-boundary dislocations (EGBDs) which disturb the ntrinsic GB structure. Stress relaxation associated to EGBDs must occur for the plastic deformation to go on and for the GB to return to equilibrium.

    5. Microstructural and Mechanical Properties of Zinc Die Casting Alloys (pages 818–822)

      M. Gelfi, E. Bontempi, A. Pola, R. Roberti, D. Rollez and L.E. Depero

      Version of Record online: 3 NOV 2004 | DOI: 10.1002/adem.200400087

      Microstructure and tensile properties of thin walled zinc diecasting alloys have been studied by means of X-Ray microdiffraction, metallographic analysis and tensile tests in order to evaluate the correlation between the elastic modulus and the component thickness. Results revealed a strong influence of skin layer microstructure on samples stiffness.

    6. Stoichiometry Defect at Grain Boundary Observed by Nano-Scale TEM Microanalysis in Spinel MgAl2O4 (pages 822–825)

      N. Nuns, F. Béclin and J. Crampon

      Version of Record online: 3 NOV 2004 | DOI: 10.1002/adem.200400083

      Spinel presents a grain boundary sliding deformation accommodated by diffusion during creep at high temperature. A space charge layer at grain boundary in ionic ceramics can explain the observed interface reaction controlling diffusion at low stress. The purpose of this work is to study the grain boundary region stoichiometry to confirm this theory.

    7. Thickness Dependent Loss Function of Si with 0.14 eV Energy Resolution (pages 826–828)

      M. Stöger-Pollach, C. Hebert, H.W. Zandbergen and P. Schattschneider

      Version of Record online: 3 NOV 2004 | DOI: 10.1002/adem.200400085

      Si band gap spectra were recorded by using electron energy loss spectrometry with very high energy resolution of 0.14 eV using a transmission electron microscope with a monochromated electron source. The shape of the spectra change with thickness, becoming indistinct at very thin regions. But even for higher thicknesses structureal evolution of the spectra can be observed. A comparison with band structure calculations is given, too.

    8. X-ray Diffraction Studies of Free-Standing Electrodeposited Cu-patterns (pages 828–832)

      K. Pantleon, H.M. Jensen and M.A.J. Somers

      Version of Record online: 3 NOV 2004 | DOI: 10.1002/adem.200400089

      Free-standing Cu-line patterns with various line widths and interline distances in the range of a few micrometers were electrodeposited. X-ray diffraction (XRD) was applied for quantification of crystallographic texture and XRD-peak broadening studies in dependence on the Cu-line dimensions. Supplementary to XRD, finite element modeling of the strain distribution within individual Cu-lines was carried out.

    9. Neutron Reflectivity as Method to Study in-Situ Adsorption of Phospholipid Layers to Solid-Liquid Interfaces (pages 832–836)

      T. Gutberlet, B. Klösgen, R. Krastev and R. Steitz

      Version of Record online: 3 NOV 2004 | DOI: 10.1002/adem.200400093

      The design and structure of biomimetic films along a planar surface is of tremendous interest for the development of biocompatible interfaces, the construction of biosensors based on membrane receptors, and as biophysical model systems for studying the interaction of biomolecules with membrane surfaces. A basic step in the design of such systems is the preparation of phospholipid molecules in the form of planar bilayers along adequate interfaces to mimic the interface of a biological membrane.

    10. High-Temperature Speciation Studies of Al-Ion Hydrolysis (pages 836–839)

      K. Shafran, O. Deschaume and C.C. Perry

      Version of Record online: 3 NOV 2004 | DOI: 10.1002/adem.200400058

      Preliminary results of a multi-technique study for Al-ion speciation are presented for the formation of large aluminium polycations. Information on the reaction pathway may aid the development of routes to solutions containing single species that can be used in model studies to investigate the effects of aluminium in the environment as well as for the generation of Al-containing materials from molecular scale precursors.

    11. Synthesis, Characterization and Crystal Structure of a new Cobalt Borophosphate, NaCoH2BP2O9 (pages 840–842)

      A. Guesmi and A. Driss

      Version of Record online: 3 NOV 2004 | DOI: 10.1002/adem.200400088

      A new sodium cobalt hydrogen borophosphate, NaCoH2BP2O9, was synthesized by the mild hydrothermal method and the crystal structure was characterized by the single-crystal x-ray diffraction method]. The structure consists in anionic groups [(H2BP2O9)3-]2 (centrosymmetric units [HP(2)O3O1/2-HBO2O2/2-P(1)O3O1/2]2) which are interconnected by sharing corners with the Co2O10 bioctahedral units. The framework connection is reinforced by hydrogen bonds.

    12. Molecular Self-Assembly and Nanomanipulation – Two Key Technologies in Nanoscience and Templating (pages 843–847)

      W.M. Heckl

      Version of Record online: 3 NOV 2004 | DOI: 10.1002/adem.200404493

      If at some time in the future we will want to build objects out of single atoms and molecules so that we can manufacture them with molecule assembly machines then we must think about which techniques need to be mastered in order to move things on the scale of atoms or molecules.