The effect of composition segregation of mold powder produced by spray granulation on the sintering performance

The composition uniformity of mold fluxes particles produced by spray granulation has an essential influence on its properties. Therefore, in the paper, the distribution of composition in mold fluxes during the heating process and the corresponding effect on the sintering properties of mold flux was comprehensively considered through TG-DSC, XPS, XRF, XRD, ICP, Infrared absorption, SEM-EDS, and sintering measurement. The results showed that: The difference in outward diffusion ability of different raw materials in the granulation process led to the enrichment of Na and C on the surface of mold flux particles. The partial aggregation of Na induced the centralized generation of sintering phase cuspidine (Ca4Si2O7F2) to inhibit the sintering of mold flux, and the sintering of mold flux can be hindered by increasing the particle size of mold flux to adjust the uniformity of mold flux composition.