The influence of melt composition, liquidus temperature and solidus temperature on vapour explosions in melt droplet impingement experiments

For the investigation of vapour explosions, droplet impingement experiments were performed with the binary system Pb-Sn and the pseudo-binary system PbS-Cu2S. The experiments were performed with a melt at 600 degrees C (Pb-Sn) or 700 degrees C (PbS-Cu2S) and a water bath at ambient temperature and pressure. A hydrophone and a highspeed camera were used to study the interaction and from this data, the explosion probability and intensity were determined.The explosion probability had a single minimum around 70 wt% Sn, close to the eutectic composition. Moreover, the explosion probability increased approximately linearly with changing composition towards the pure melts, and was similar for pure tin and pure lead. On the other hand, the explosion intensity was comparable for tin and the eutectic alloy while clearly lower for lead. Almost all intermediate alloys had a reduced explosion intensity.Based on the variation in composition, the effects of the liquidus or solidus temperature and the liquidussolidus gap on the explosion behaviour were also investigated. The explosion probability in both systems increased with increasing liquidus temperature. Also, the maximum explosion intensity in the Pb-Sn system increased with increasing liquidus temperature. Both could be related to easier triggering due to (partial) solidification. On the other hand, the explosion intensity was found to decrease with increasing gap between liquidus and solidus temperature, as was also found in literature. No significant trends for the explosion intensity were found for experiments with PbS-Cu2S.