Effects of TiO₂ on nonisothermal crystallization process of casting mold fluxes

The nonisothermal crystallization behavior of mold fluxes bearing various TiO₂ was studied by using the single hot thermocouple technique.The mineral components of the mold fluxes were analyzed by X-ray diffraction (XRD) and microscopically observed by mine-phase microscope.The results indicate that cuspidine is the main phase of the casting mold fluxes.With a certain amount of TiO₂ (2% to 8%) added into the mold fluxes at high basicity (ΣR=1.3),the phase precipitation increases.Small amount of Ca₂SiO₄,Ca₂Al(AlSi₇O₇),Ca₂SiO₂F₂ and CaTiO₃ are crystallized.While the time of crystallization process of the mold fluxes is lengthened,the crystallization ratio and crystallization rate of the mold fluxes is decreased.Thus,crystallization of the mold fluxes is inhibited,leading to improvement in the glass property and the lubrication between casting strands and molds in view of the heat flow control of slag films.