Synthesis and characterization of β-Sialon powders from Si, halloysite clay and AlN powders

Abstract

Two [Formula: see text]-Sialons, with [Formula: see text]-values of 1 and 4, respectively, were successfully synthesized by silicothermal reduction and nitridation method under 0.4 MPa nitrogen pressure. The effect of firing temperatures on the phase transformations and morphologies of [Formula: see text]-Sialons were analyzed by XRD and SEM. For [Formula: see text]-Sialons ([Formula: see text]), the product was finally composed of targeted [Formula: see text]-Sialon ([Formula: see text]) and secondary phase [Formula: see text]-Si3N4; for [Formula: see text], [Formula: see text]-Sialon ([Formula: see text]) was the main phase, and 15R-Sialon and [Formula: see text]-Al2O3 co-existed as secondary phases. A higher firing temperature is more beneficial for the phase transformations and crystal growth of [Formula: see text]-Sialons, however, the most suitable firing temperature was 1400[Formula: see text]C.