1：Experimental Design and Method Selection:

β-Sialon powders were synthesized using salt-assisted nitridation with Al, Si, and SiO2 powders in a molten salt medium of NaCl and NaF, with varying NaN3 contents as an auxiliary nitrogen source, at temperatures from 1250-1450°C for 3 hours under nitrogen atmosphere.

2：Sample Selection and Data Sources:

Raw materials included Al (≥

3：0%, 05 mm), Si (≥9%, 9 μm), SiO2 (≥0%, 15 μm), NaCl (≥0%), NaF (≥0%), and NaN3 (≥0%). List of Experimental Equipment and Materials:

A corundum crucible and tubular corundum furnace were used for heating; ultrasonic equipment for washing; X-ray diffraction (XRD, Philips, X’Pert Pro) for phase analysis; scanning electron microscope (SEM, Nova NanoSEM400, FEI Company) for morphology observation.

4：Experimental Procedures and Operational Workflow:

Mixtures with specific weight percentages (e.g., 10 wt% Al, 7 wt% Si, 15 wt% SiO2, 65 wt% NaCl, 3 wt% NaF, and varying NaN3 contents) were loaded into a corundum crucible, heated in the furnace under nitrogen (

5：99% purity) at set temperatures for 3 hours, then washed with distilled water using ultrasonic equipment to dissolve salts, and dried to obtain products. Data Analysis Methods:

XRD was used for phase identification, and SEM with ImagePro software for morphology and size analysis.