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

Ali Talimian; Vaclav Pouchly; Karel Maca; Dusan Galusek

doi:10.3390/ma13010102

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

Materials (Basel). 2019 Dec 24;13(1):102. doi: 10.3390/ma13010102.

Authors

Ali Talimian¹, Vaclav Pouchly^{2

3}, Karel Maca^{2

3}, Dusan Galusek^{1

4}

Affiliations

¹ Centre for Functional and Surface Functionalised Glass, Alexander Dubcek University of Trencin, 91150 Trencin, Slovakia.
² CEITEC BUT, Brno University of Technology, Purkynova 123, 62100 Brno, Czech Republic.
³ Faculty of Mechanical Engineering, Brno University of Technology, Technicka 2, 62100 Brno, Czech Republic.
⁴ Joint Glass Centre of the IIC SAS, TnUAD and FChPT STU, 91150 Trencin, Slovakia.

Abstract

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.

Keywords: MgAl2O4; cobalt fluoride; grain growth; lithium fluoride; manganese fluoride; spark plasma sintering.

Abstract

Grants and funding