Materials (Dec 2019)

Densification of Magnesium Aluminate Spinel Using Manganese and Cobalt Fluoride as Sintering Aids

  • Ali Talimian,
  • Vaclav Pouchly,
  • Karel Maca,
  • Dusan Galusek

DOI
https://doi.org/10.3390/ma13010102
Journal volume & issue
Vol. 13, no. 1
p. 102

Abstract

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Highly dense magnesium aluminate spinel bodies are usually fabricated using pressure-assisted methods, such as spark plasma sintering (SPS), in the presence of lithium fluoride as a sintering aid. The present work investigates whether the addition of transition metal fluorides promotes the sintering of MgAl2O4 bodies during SPS. At the same time, such fluorides can act as a source of optically active dopants. A commercial MgAl2O4 was mixed with 0.5 wt% of LiF, MnF2, and CoF2 and, afterwards, consolidated using SPS at 1400 °C. Although MnF2 and CoF2 promote the densification as effectively as LiF, they cause significant grain growth.

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