Effect of boron on surface tension of liquid Fe-3.0%Si alloys

Abstract

Based on Butler and Toop models, the surface tensions of liquid Fe-3.0%Si (wt.%, same as below) alloys with different Boron (B) additions were calculated. Meanwhile, the surface tensions of Fe-3.0%Si and Fe-3.0%Si-0.5%B alloys at 1550–1650 °C were also measured with the sessile drop method. The calculated results indicated that the surface tension of liquid Fe-3.0%Si alloys decreased with the increase of B content from 0.5% to 2%, which is in good agreement with the measured results. Si and B with lower surface tension tend to aggregate on the surface of the liquid alloy, while Fe with higher surface tension tends to aggregate inside the liquid alloy. With temperature increased from 1550 to 1650 °C, the surface concentration of each element is approaching the ideal concentration. Finally, a linear fit is used to correct β values. When β values are between 0.762–0.867, the calculated results of Fe-3.0%Si and Fe-3.0%Si-0.5%B alloys are close to the experimental results.

Keywords

• Fe-3.0%Si alloys
• Surface tension
• Butler model
• The sessile drop method