Sintering behavior of magnesium aluminate spinel MgAl ₂ O ₄ synthesized by different methods

Abstract This paper is focusing basically on the ceramic technology, of which several methods for the synthesis of MgAl ₂ O ₄ have been investigated. The synthesis conditions regarding the powders cleanliness, microstructure, and sintering parameters of MgAl ₂ O ₄ were studied. MgAl ₂ O ₄ powder was synthesized via conventional solid‐state route using different milling process: vertical attrition milling, WAB as a high‐energy horizontal attrition milling, and Pulverisette as a planetary ball miller, and via solution combustion route using Urea, Glycine, and a mixture of Urea/Glycine. Urea and Glycine was used as fuel. The white powders were obtained for all solid‐state routes and for Urea‐combustion technique. The black and gray powders were obtained in the case of combustion technique, respectively, using a fuel of Glycine and Glycine/Urea mixture. The obtained powders and pellets were characterized by XRD , SEM , and Dilatometry. The results show that, among all the solid‐state route processes, wet attrition milling gives the better and clean spinel phase. The WAB milling and Pulverisette miller introduce a contamination by some yttria‐stabilized zirconia balls in the corresponding powder. Furthermore, the flash combustion technique permit to have nanoparticles with a dense spinel phase of MgAl ₂ O ₄ and with lower sintering temperature in less time and with no calcination step.