Microwave sintering of nanosctructured metallic powders

Cristina Leonelli ,  Roberto Rosa ,  Paolo Veronesi 

Microwave Application Group-MAG, Department of Engineering Enzo Ferrari, University of Modena and Reggio Emilia, Via Vignolese 905, Modena 41125, Italy


 Electromagnetic field assisted sintering techniques (FAST) demonstrated the possibility to minimize the grain growth, obtaining, at the same time, final densities near to the theoretical ones. Besides the high speed of the process, this can be ascribed also to a series of phenomena, like electromigration, the local increase of the diffusion coefficient or the action of ponderomotive forces. Very soon, among these techniques, microwave (MW) assisted sintering reached a strong experimental evidence of accelerated densification, lower porosity and achievement of peculiar microstructuresin the final products, including metal-based ones [1, 2].

In this work, nanostructured stainless steel powders, obtained by high energy milling have been uniaxially pressed in order to obtain 20 mm diameter cylindrical compacts. Microwave sintering of the green compacts has been performed in a single mode microwave applicator, at 2.45 GHz.

Maximum sintering temperature of each sample, monitored using a sapphire optical fibre, was varied in the 900-1150 °C range. Microwave forward power was varied accordingly, in order to maintain sintering times in the 120- 500 seconds range.

Rapid microwave sintering helps maintaining the nanostructure, despite a non homogenous densification due to the uneven electromagnetic field distribution in the single-mode applicator. A more homogenous multi-mode applicator, as well as the samples movement during sintering helped increasing the homogeneity and simultaneously sintering multiple green parts. Numerical simulation of the electromagnetic field distribution inside the multi-mode applicator allowed to select the best experimental conditions in terms of samples homogeneity and energy efficiency. 


[1] R. Roy, D. Agrawal, J. Cheng, S. Gedevanishvili, Full sintering of powdered metal bodies in a microwave field, Nature 399, 1999, 668-670.

[2] C. Leonelli, P. Veronesi, L. Denti, A. Gatto, L. Iuliano, Microwave assisted sintering of green metal parts, J. Mater. Proc. Technol. 205, 2008, 489-496.

Auxiliary resources (full texts, presentations, posters, etc.)
  1. PRESENTATION: Microwave sintering of nanosctructured metallic powders, PDF document, version 1.5, 1.3MB
  2. CV: Note about author(s): Cristina Leonelli, Roberto Rosa, Paolo Veronesi, PDF document, version 1.5, 0MB

Legal notice
  • Legal notice:

    Copyright (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 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/31193 must be provided.


Related papers
  1. Characterization of nanopowders
  2. Microwave technique applied on the hydrothermal synthesis and sintering of calcia stabilized zirconia nanoparticles
  3. Microwave asssited hydrothermal synthesis as a rapid route toward manganites preparation
  4. A method for procedural standardisation for preparing and processing nanopowders using microwaves
  5. Conventional thermal process versus microwave hydrothermal accelerated synthesis route of lanthanum manganites perovskites used in methane combustion
  6. Ultrasonic and Microwave Assisted Synthesis of Nanometric Particles
  7. Investigations of phase composition and grain size distribution in Pr doped ZrO2
  8. Grain Size and Grain Size Distribution of Nanocrystalline Pr-doped Zirconia Powders Obtained in High Pressure Microwave Reactor
  9. Measuring the Grain Size Distribution of Pr-doped Zirconia Nanopowders obtained by Microwave Driven Hydrothermal Synthesis
  10. Microwave driven hydrothermal synthesis of Pr-doped zirconia nanopowders

Presentation: Invited Oral at Nano PL 2014, Symposium A, by Cristina Leonelli
See On-line Journal of Nano PL 2014

Submitted: 2014-04-03 14:00
Revised:   2014-11-18 14:02
Web science24.com
© 1998-2021 pielaszek research, all rights reserved Powered by the Conference Engine