Formation and reactivity of nitrides. III. Boron, aluminium and silicon nitrides

Abstract

Abstract The reactivities of boron, aluminium and silicon nitrides have been compared. Samples of these nitrides have been converted to oxides by being calcined in air. Changes in phase composition, surface area, crystallite and aggregate sizes have been correlated with oxidation time and temperature. Crystallites of alumina, α‐Al 2 O 3 , split off from the remaining aluminium nitride before they sinter and inhibit further oxidation. The diboron trioxide, B 2 O 3 , and silica, SiO 2 (α‐cristobalite), immediately act as mineralisers for the remaining boron and silicon nitrides, and progressively retard the oxidations.