Effect of diluents on high purity β-SiAlONs by mechanically activated combustion synthesis

Abstract

The influence of diluent addition on purities of β-Si₅AlON₇ powders synthesized by mechanically activated combustion synthesis (MA-CS) under a very low nitrogen atmosphere of 1 MPa was investigated. The purity of β-Si₅AlON₇ powders increased with diluent concentrations in raw materials and had a maximum value of 91% when 40 mass% of diluents were added, a 25% more pure when compared to powders procured without diluents. In contrast, when diluents were included 50% or more, the combustion synthesis (CS) reaction did not occur due to reduced exothermic heat. The results also showed that the particle sizes of β-Si₅AlON₇ powders synthesized with 40 mass% of diluents were only one-tenth when compared to powders synthesized without diluents.