Advanced Engineering Materials

Cover image for Advanced Engineering Materials

April, 2004

Volume 6, Issue 4

Pages 185–265

    1. Contents: Adv. Eng. Mater. 4/2004 (pages 185–188)

      Article first published online: 28 APR 2004 | DOI: 10.1002/adem.200490002

    2. Polymer Nanocomposites for Aerospace Applications: Fabrication (pages 193–203)

      J. Njuguna and K. Pielichowski

      Article first published online: 28 APR 2004 | DOI: 10.1002/adem.200305111

      Nanocomposite polymers have tremendous potential to enhance the performance of macromolecular materials used for composite matrices. Effective utilization of carbon nanotubes in composite applications depends strongly on the ability to homogeneously disperse them throughout the matrix without destroying their integrity. This work looks at the fabrication for montmorillonite, fullerenes and nanotube polymer/nanocomposites tailored to fit aerospace needs.

    3. Polymer Nanocomposites for Aerospace Applications: Characterization (pages 204–210)

      J. Njuguna and K. Pielichowski

      Article first published online: 28 APR 2004 | DOI: 10.1002/adem.200305110

      Development of modern characterization techniques have played a key role in development of characterisation and parametric study on polymer nanocomposites starting from the molecular level. The current work reviews the ongoing investigations and techniques to overcome the challenges posed by polymer nanocomposites characterisation.

    4. A Novel Pulse-Current-Assisted Sintering Method for Fabrication of Metallic Cellular Structures (pages 211–214)

      Z. Song, S. Kishimoto and N. Shinya

      Article first published online: 28 APR 2004 | DOI: 10.1002/adem.200300577

      A novel isostatic pressing method by spark plasma sintering system is presented for the fabrication of cellular metals. It is a faster and more flexible sintering method compared with traditional hot pressing. The authors show that cellular metal with fine and controllable structure can be fabricated by this method.

    5. Strengthening and Embossment of Final Shape in NiTi Shape Memory Alloys (SMA) (pages 214–218)

      E. Hornbogen

      Article first published online: 28 APR 2004 | DOI: 10.1002/adem.200300571

      Shape memory alloys transform at low temperature by a martensitic reaction β [RIGHTWARDS ARROW] α , which implies formation of a domain structure (similar to ferromagnetic, ferroelectric transformations). This microstructure allows complex pseudo-plastic deformability. A systematic approach is provided for the types of reverse reactions α [RIGHTWARDS ARROW] β, which are found between crystalographically reversible (martensitic) and diffusion controlled (combined reactions). Features of optimum microstructures for shaping and desired SM-properties are discussed.

    6. Enhanced Strength and Ductility in Ultrafine-Grained Aluminium Produced by Accumulative Roll Bonding (pages 219–222)

      H.W. Höppel, J. May and M. Göken

      Article first published online: 28 APR 2004 | DOI: 10.1002/adem.200300582

      Bulk ultrafine-grained (UFG) materials, produced by severe plastic deformation (SPD) have recently received considerable scientific attention. In this work the authors explore, whether the so-called “paradox of ductility and strength” is also true for UFG Aluminium produced by an Accumulative Roll Bonding (ARB) process and to clarify the effect of the SPD-related pre-deformation on the stress-strain behaviour.

    7. Material Flow During Equal Channel Angular Pressing of Aluminum Containing Al8Fe2Si Precipitates (pages 222–228)

      A. Korchef, N. Njah, Y. Champion, S. Guérin, C. Leroux, J. Masmoudi and A. Kolsi

      Article first published online: 28 APR 2004 | DOI: 10.1002/adem.200300570

      99.1% aluminium containing Al8Fe2Si precipitates located at grain boundaries, was deformed by ECA pressing. Evolution of the plastic flow was evaluated from the spatial distribution of precipitates characterized by Optical Microscopy. The theoretical models of the deformation, based on simple shear, fit with the experimental results for the number of passes N=1 and 2. For further pressings, discrepancies are observed, indicating that more complex deformation processes may be operative.

    8. Austenitic Stainless Steels from Quantum Mechanical Calculations (pages 228–232)

      L. Vitos, P.A. Korzhavyi and B. Johansson

      Article first published online: 28 APR 2004 | DOI: 10.1002/adem.200300555

      Quantum mechanics is used to study the influence of the chemical composition on the elastic properties of austenitic stainless steels. Fe based alloys comprising approximately 15% Cr and 8% Ni are predicted to have the largest hardness among the usual austenitic steels, which, however, is associated with increased brittleness and susceptibility to various forms of localized corrosion. It is shown that few percent of additional Os or Ir to Fe15Cr8Ni alloy significantly improve on both of these shortcomings, without deteriorating the hardness.

    9. Novel Crosslinking of High-order and Multiple Copper Twins in Advanced Microelectronics Packaging (pages 232–234)

      W. Zhang, C.-Z. Liu, D.-X. Li and M.-L. Sui

      Article first published online: 28 APR 2004 | DOI: 10.1002/adem.200300540

      Novel crosslinking of high-order and multiple copper twins has been formed in the metallization/solder interconnect subjected to the thermal aging. This surprising finding may illustrate a universal metallization failure mode. Meanwhile, many copper nanocrystals in situ originated from those twins crosslinking shed a novel light on the synthesis approach to fascinating nanocrystalline metals.

    10. Superparamagnetic Silica-Iron Oxide Nanocomposites for Application in Hyperthermia (pages 235–241)

      M. Chastellain, A. Petri, A. Gupta, K.V. Rao and H. Hofmann

      Article first published online: 28 APR 2004 | DOI: 10.1002/adem.200300574

      Superparamagnetic iron oxide particles embedded in silica are studied for application in hyperthermia. The temperature increase is studied when submitting the samples to a weak alternating magnetic field. The influence of the iron oxide size distribution, saturation magnetization, out of phase susceptibility and anisotropy constant is discussed. A theoretical calculation of power loss is carried out and agrees with experimental data.

    11. Sol–Gel Template Synthesis of Aluminum Oxide Microtubules (pages 241–244)

      T. Peng, H. Yang, K. Dai, K. Nakanishi and K. Hirao

      Article first published online: 28 APR 2004 | DOI: 10.1002/adem.200300573

      Al2O3 microtubules with ca. 60–600 μm in lengths and 2–16 μm in outer diameter have been prepared using water-soluble ammonium tartrate crystal as a template in a sol-gel method using aluminum sec-butoxide (ASB) as starting materials, which may have potential application in catalytic materials, electronic science or separation technology.

    12. Ceramics in Nanotech Revolution (pages 244–247)

      A. Arora

      Article first published online: 28 APR 2004 | DOI: 10.1002/adem.200300532

      ‘Nanotechnology’, called the materials technology of 21st century has also entered the field of ceramics. Nanoceramic systems, their synthesis, characterization and the changed properties in view of chemistry of nanoparticles are discussed along with the applications of nanoceramics. In the end the major challenges being encountered like scaling-up the synthesis of nanoceramics for development of industrial scale methods are discussed

    13. Selection of Applications for a Material (pages 249–265)

      A. Salimon, Y. Bréchet, M.F. Ashby and A.L. Greer

      Article first published online: 28 APR 2004 | DOI: 10.1002/adem.200400002

      Finding an application for a given (not necessarily new) material is an elusive problem. Methods for material selection to fill a given application are now well developed. But the inverse problem – that of finding applications for a new material – has no such established methodology. The article discusses some general approaches to the problem and demonstrates recent progress in implementing them.