熔体过热对Sb-Bi合金凝固组织的影响

Effect of melt superheating on solidified structure of a Sb-Bi alloy

以Sb - 4.6 %Bi合金为研究对象 ,在限定其它因素保持不变的情况下 ,考察了熔体过热温度对凝固过程的影响 .实验结果发现 ,随着熔体过热温度的提高 ,合金形核过冷度增大 ,凝固组织显著细化 .研究表明 ,熔体过冷倾向是熔体结构状态的一个必然反映 ,熔体结构状态随温度发生变化是导致合金结晶过冷度发生明显变化的原因 ;随着过热温度的提高 ,Sb - 4.6 %Bi合金晶粒显著细化 。

This paper takes the Sb-4.6%Bi alloy as the object of study. The influence of melt superheating temperature on solidification process is examined while other factors are kept constant. It is found that the tendency of the melt to supercooling is an inevitable reflection of the melt structure and its change with temperature. The grain size of the Sb-4.6%Bi alloy can be greatly refined with the increase of superheating temperature. This is because that the melt treated with superheating solidifies with comparatively higher degree of supercooling.