Synthesis and densification of transparent magnesium aluminate spinel by SPS processing Academic Article uri icon


  • Abstract Mixtures of elementary oxides, MgO–Al 2 O 3, were used to fabricate transparent polycrystalline magnesium aluminate spinel specimens by means of the spark plasma sintering technique. A sintering aid, 1 wt% of LiF, was added to the mixed powder. The presence of the additive promotes the synthesis of spinel that starts at 900 C and is completed at 1100 C. The LiF additive wets spinel on its melting and promotes densification, which is completed at 1600 C. LiF vapor plays a cardinal role in eliminating residual carbon contamination and in the fully dense state, allows attaining a 78% level of optical transmittance. The optimal conditions for achieving adequate transparency were determined and the role of the LiF addition in the various stages of the process is discussed.

publication date

  • January 1, 2009