Sintering of icosahedral quasicrystalline Al-Cu-Fe powders using high quasihydrostatic pressure

Mykola O. Yefimov ,  Yuly V. Milman ,  Dina V. Lotsko ,  Sergey V. Ulshin ,  Izabella I. Timofeeva ,  Miroslav V. Karpets ,  Olexander I. Bykov 

Institute for Problems of Materials Science, 3, Krzhizhanovsky, Kyiv 03142, Ukraine

Abstract

The processes accompanying the sintering of quasicrystalline Al-Cu-Fe powders were investigated. Pure Al-Cu-Fe powders and powders alloyed by 0.3 wt.% Sc and 11 wt.% Cr were chosen for studies. Quasicrystalline powders were produced by water atomization technique. The technology of sintering with high quasihydrostatic pressure was used. High-temperature sintering under high quasihydrostatic pressure was realized in the high-pressure cell of “lentil” type. Sintering was carried out at 700 С during 2 min using the pressure range from 2.8 up to 7 GPa. The optimum pressure of preliminary cold pressing (0.6 GPа) and high temperature pressing (3-4 GPа) were determined. The compacts with porosity < 2% were obtained. The phase compositions of compacts were studied by X-ray diffractometry and SEM techniques. Microhardness was measured by Vickers indenter at a load of 2 N. Using the original technique developed by authors the plasticity characteristic δH of the sintered quasicrystalline compacts was determined from the microhardness values as well.
The annealed Al-Cu-Fe and Al-Cu-Fe-Sc compacts were obtained in the single-phase quasicrystalline state whereas the Al-Cu-Fe-Cr compacts - in the single-phase approximant state.
It is revealed that microhardness of sintered compacts noticeably lowers with the growth of the sintering pressure, whereas line broadening in X-ray patterns of compacts increases. The analysis of line broadening in X-ray patterns has shown a progressive growth of the density of phason defects in quasicrystalline lattice with increasing the sintering pressure.
The stress-strain curves were obtained for all sintered compacts. The stages of strengthening and softening are observed for all deformation curves. However, the softening stage on deformation curve of Al-Cu-Fe-Cr compacts (approximant phase) is shorter than for the samples of the quasicrystalline phase. In all sintered compacts the δH=0.67-0.70.

Legal notice
  • Legal notice:

    Copyrighted materials, (c) Pielaszek Research, all rights reserved.
    The above materials, including auxiliary resources, are subject to Publisher's copyright and the Author(s) intellectual rights. Without limiting Author(s) rights under respective Copyright Transfer Agreement, no part of the above documents may be reproduced, stored in or introduced into a retrieval or caching system, or transmitted in any form or by any means (electronic, mechanical, photocopying, recording or otherwise), or for any purpose, without the express written permission of Pielaszek Research, the Publisher. Express permission from the Author(s) is required to use the above materials for academic purposes, such as lectures or scientific presentations.
    In every case, proper references including Author(s) name(s) and URL of this webpage: http://science24.com/paper/3457 must be provided.

 

Related papers
  1. Features of mechanical behavior of isotropic composites with metallic matrix
  2. Investigation of contact interaction of metal melts and non metal materials by high temperature X-ray diffraction method
  3. Peculiarities of mechanical behavior of nanocrystalline and noncrystalline materials
  4. Role of plastic deformation in sintering powders
  5. Sintering of Germanium Single Crystals in Different P-T Conditions
  6. Microstructure of Surface Layers of Raiways After Heavy Exploatation
  7. On the Correlation of Mechanical Behaviour of Ceramic Materials Under Shock Compression and Static Intendation
  8. High-Strength Aluminum-Based Alloys Hardened by Quasicrystalline Nanoparticles
  9. Indentation Technique for Determination if Mechanical Behavior of Nanomaterials (Bulk and Coatings)

Presentation: poster at E-MRS Fall Meeting 2005, Symposium I, by Mykola O. Yefimov
See On-line Journal of E-MRS Fall Meeting 2005

Submitted: 2005-05-04 14:53
Revised:   2009-06-07 00:44
Google
 
Web science24.com
© 1998-2021 pielaszek research, all rights reserved Powered by the Conference Engine