The relationship between crystallization and break temperature of mould flux

ABSTRACT

Many researchers believe that crystallization is responsible for drastic viscosity changes near the break temperature of mould flux; however, there are no reasonable experimental data to support this view. In this study, the complete crystallization process is recorded in situ by inhibiting the volatilization of fluoride, and the relationship between viscosity change and crystallization near the break temperature is studied. Mould flux with a basicity of 0.65 had no break temperature, and no crystallization occurs within the temperature range of the viscosity test. The other three mould fluxes begin to crystallize before the break temperature, but the crystal volume fractions at the break temperature are different. The break temperature of mould flux is the crystallization temperature with a critical crystal volume fraction, which is related to the viscosity before the break temperature. The higher the viscosity, the smaller the critical crystal volume fraction. Therefore, break temperature ≤ initial crystallization temperature.

KEYWORDS:

• Break temperature
• viscosity
• crystal volume fraction
• volatilization

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

The State Key Program of National Natural Science of China [grant number U1660204], National Natural Science Foundation of China [project number 51874057] are acknowledged for supporting this work.