Development of AlN and TiB₂ Composites with Nb₂O₅, Y₂O₃ and ZrO₂ as Sintering Aids.

The synthesis of AlN and TiB₂ by spark plasma sintering (SPS) and the effect of Nb₂O₅, Y₂O₃ and ZrO₂ additions on the mechanical properties and densification of the produced composites is reported and discussed. After the SPS process, dense AlN and TiB₂ composites with Nb₂O₅, Y₂O₃ and ZrO₂ were successfully prepared. X-ray diffraction analysis showed that in the AlN composites, the addition of Nb₂O₅ gives rise to Nb₄N₃ during sintering. The compound Y₃Al₅O12 (YAG) was observed as precipitate in the sample with Y₂O₃. X-ray diffraction analysis of the TiB₂ composites showed TiB₂ as a single phase in these materials. The maximum Vickers and toughness values were 14.19 ± 1.43 GPa and 27.52 ± 1.75 GPa for the AlN and TiB₂ composites, respectively.