Corrosion of combustion-synthesized β-SiAlONs in supercritical water

The corrosion of β-Si6−zAlzOzN8−zs (z = 1, 2, and 3) prepared by combustion synthesis (CS) followed by spark plasma sintering (SPS) was investigated in supercritical water at 400 °C/30 MPa for 100 h. The corrosion behavior was studied by means of gravimetry, X-ray diffraction (XRD), scanning electron microscopy (SEM)/energy dispersive X-ray spectrometer (EDS). The mass loss and corroded layer decreased with the increasing in z value, and the results of XRD showed the oxide formed on β-SiAlONs (z = 1, 2, and 3) is aluminum silicate (Al2SiO5). Finally, we proposed the reaction mechanism of these materials in supercritical water.

► The corrosion of β-Si6−zAlzOzN8−zs (z = 1, 2, and 3) has been investigated in SCW under 400 °C/35 MPa for 100 h.
► The corrosion behavior of these materials is studied using XRD, SEM, and EDS.
► The reaction mechanism of β-Si6−zAlzOzN8−zs in supercritical water is proposed.
► The results in this study could present a valuable example for similar studies.