A benchmark solidification experiment on an Sn–10%wtBi alloy

The solidification of a 90/10%wt tin–bismuth alloy has been analyzed experimentally for a 50 × 60 × 10 mm ingot. The heat flux was extracted from one vertical side of the ingot. Instantaneous temperature measurements were performed using a lattice of 25 thermocouples located on one of the large sides of the sample. The temperature versus time curve exhibits the classical pseudo-plateau as well the eutectic step. A post-mortem analysis of the samples was carried out. Solidification is almost columnar over the range of solidification rates considered. Two types of segregations are observed. X-ray analysis reveals the development of segregated channels near the cold wall. Analysis of the solute composition shows the existence of significant macro-segregations. The locations of the segregations are confirmed by the measurements of the eutectic fraction.