Densification Mechanism of MgAl2O4 Spinel during Spark-Plasma-Sintering


ISSN 1121-7588
Koji Morita1, Byung-Nam Kim1, Hidehiro Yoshida1, Keijiro Hiraga1, Yoshio Sakka2
1
National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047, Japan
2 World Premier International Research Center Initiative (WPI Initiative) on Materials Nanoarchitechtonics (MANA), National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047, Japan
 

Abstract

The densification mechanism during the park-plasma-sintering (SPS) processing was examined in high purity MgAl2O4 spinel. As the density ρt increases, that is, as the effective stress σeff decreases, stress exponent n evaluated from σeff dependence of densification rate varies from n ≥ 4 in the low ρt region, n ≈ 2 in the intermediate ρt region to n ≈ 1 in the high ρt region. TEM observation shows that significant stacking faults caused by partial dislocations are observed in the low ρt region, but limited in the high ρt region. The ρt dependent densification behavior and microstructure suggest that the predominant densification mechanism during the SPS processing changes with ρt from plastic flow by partial dislocation motion for the low ρt region (n ≥ 4) to diffusion-related creep for the high ρt region (n ≈ 1).
€ 45,00

ico-info Address
  • Sede legale : via dei Bianchi n.19
  • 47121 - Forlì (FC)
  • email: info@technagroup.it
  • R.E.A. 297724
  • reg. Imp. Forlì-Cesena
  • Capitale sociale: EURO 20.000,00 interamente versato
© Techna Group s.r.l. - Faenza (RA) - Italy - VAT IT03368230409 Daisuke Ecommerce