Concentration-induced convection of a binary metal melt in a rectangular crucible has been studied numerically in the case of a mixture with a eutectic phase diagram. The calculations are performed for realistic parameters which correspond to the pair of metals Sn-Pb. A solid rod with non-wettable boundaries and a non-uniform longitudinal temperature distribution on the surface is immersed into the melt vertically at the center of the crucible. The condition of complete non-wetting allows us to consider the interface between the melt and the rod to be free. The temperature non-uniformity leads to inhomogeneity of the surface tension. As a result, the thermocapillary force generates a steady convective flow first on the surface of the rod and then in the volume. Due to this motion, the heavy component of the alloy is transferred along the rod’s surface to the butt-end. At the boundary patches with the excess of concentration it has been extracted into the volume by means of the desorption mechanism. In the presence of weak convection in the volume, this component is partially accumulated near the bottom of the crucible under the butt-end. Thus, there takes place a process of separation of heavy admixture for the two-component metal melts.

中文翻译：

---

插入具有不可润湿边界的等温棒导致坩埚中熔体成分的定位

在具有共晶相图的混合物的情况下，已经数值研究了矩形坩埚中二元金属熔体的浓度诱导对流。针对对应于金属对Sn-Pb的实际参数执行计算。将具有不可润湿边界和表面上纵向温度分布不均匀的实心棒垂直地浸入坩埚中心的熔体中。完全不润湿的条件使我们可以考虑熔体和棒之间的界面是自由的。温度不均匀导致表面张力不均匀。结果，热毛细作用力首先在杆的表面上然后在体积中产生稳定的对流。由于这项议案，合金的重组分沿着棒的表面转移到对接端。在边界斑处，由于浓度过高，已经通过解吸机制将其提取到体积中。在对流中存在弱对流的情况下，该组分在对接端下方的坩埚底部附近部分堆积。因此，发生了分离用于两组分金属熔体的重质混合物的过程。