Journal of Materials Science

, Volume 50, Issue 5, pp 2327–2336 | Cite as

Identification of densification mechanisms of pressure-assisted sintering: application to hot pressing and spark plasma sintering of alumina

  • G. AntouEmail author
  • P. Guyot
  • N. Pradeilles
  • M. Vandenhende
  • A. Maître
Original Paper


The identification of densification mechanism during hot uniaxial pressing is developed using an approach based on classical creep investigation. This approach is justified and generalised using continuum mechanics based sintering models. The benefit of this approach is to directly determine the densification parameters from the analysis of shrinkage rates of the porous material, rather than to transpose the creep mechanisms identified for dense material at given thermomechanical conditions to the densification progress. The suggested approach is applied to compare the densification mechanisms involved at the initial stage of sintering (i.e. for 60 % < relative density < 75 %) during hot pressing (HP) and spark plasma sintering (SPS) of a submicrometric alpha-alumina powder. From the stress exponent and activation energy values, it is shown that the main mechanism involves grain boundary sliding accommodated by dislocation motion and particle fracture in both cases. However, it appears that, in SPS, the high heating rate could reduce the existence of surface diffusion phenomena at the beginning of the consolidation process, as suggested by the higher activation energy compared to the one determined for HP.


Apparent Activation Energy Spark Plasma Sinter Stress Exponent Grain Boundary Slide Shrinkage Rate 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.



This work was carried out within the IMPULSE project, thanks to the financial support of the French National Research Agency (ANR). The authors gratefully thank the group of Dr Claude ESTOURNES (CIRIMAT Institute) and the PNF2 team for their help in carrying out SPS experiments.


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Copyright information

© Springer Science+Business Media New York 2014

Authors and Affiliations

  • G. Antou
    • 1
    Email author
  • P. Guyot
    • 1
  • N. Pradeilles
    • 1
  • M. Vandenhende
    • 1
  • A. Maître
    • 1
  1. 1.Laboratoire Sciences des Procédés Céramiques et Traitements de Surface, UMR CNRS 7315, Centre Européen de la CéramiqueLimoges CedexFrance

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