Predicting the Adiabatic Temperature of Transparent Y₃Al₅O₁₂ Prepared via Combustion Synthesis under Ultra-High Gravity

Abstract

In this paper, the adiabatic temperature of a transparent yttrium aluminum garnet (YAG) preparation using a NiO/Al/Y₂O₃ aluminothermic system was calculated based on a thermodynamic theory. The results show that the adiabatic temperature without preheating reaches the 2891 K, which is higher than the melting points of YAG and Ni. The liquid phase mixture products can be separated and densified under ultra-high gravity (UHG). In the preheating temperature range of 620K∼2790K to the reactants of this system, the adiabatic temperature is the same as 3156 K, the boiling point of Ni products. The theoretical analyses and experimental results prove the effectiveness of the YAG fabricated via combustion synthesis under an ultra-high gravity field.