Evaluation of Surface Tension of CaO–SiO₂–Al₂O₃‐Based Mold Flux Containing Ce₂O₃

The calculation model based on the surface tension of CaO–SiO 2 –Al 2 O 3 ‐based mold flux containing Ce 2 O 3 is studied using the modified Butler equation, and the surface tension of mold flux is measured by the sessile drop method. The experimental results show that the calculated surface tension based on the model agrees well with the experimental values, and the absolute value of the error is less than 3.23%. With the content of Ce 2 O 3 in the mold flux increasing from 0% to 20%, the surface tension of the mold flux increases from 0.380 to 0.405 N m −1 . The O 2− dissociated from Ce 2 O 3 makes the radius of the silicon–oxygen tetrahedral anion decrease, and the ion‐to‐ion interaction force in the melt increase. Therefore, the surface tension of the melt increases with the increase of Ce 2 O 3 content in the mold flux. However, the amount of dissociated O 2− is limited, so the effect of Ce 2 O 3 on the surface tension of the mold flux is limited.