Combustion synthesis of yttria

Abstract

Fine-particle, sinter-active yttria has been prepared by combustion of a redox compound, Y(N₂H₃COO)₃·3H₂O and mixtures of Y(N₂H₃COO)₃·3H₂O–NH₄NO₃ or NH₄ClO₄ as well as yttrium nitrate and hydrazine-based fuels. The fineparticle nature of the combustion-derived yttria has been investigated using powder density, particle size and BET surface area measurements. The uniaxially, cold-pressed fine-particle yttria when sintered at 1450–1500 °C achieved 98% theoretical density and showed a fine-grain (1–2 µm) microstructure.