A new route to synthesize β-Si6−zAlzOzN8−z powders

β-Sialons (Si6−zAlzOzN8−z) of z values ranging between 1 and 4 were tried for combustion synthesis using mechanically activated powders of Si, Al and Al2O3 with desired mixing ratio in a pressurized nitrogen atmosphere of 1 MPa. The starting materials were milled to 18 min using a planetary ball mill for mechanical activation (MA). Unsuccessful propagations of z values 1 and 2 were explained in terms of amount of Al present in the raw material. Waste Si, of 94.8 mass% in purity, obtained from semiconductor industry was also introduced as a raw material to replace commercially available Si for the combustion synthesis.