Wetting and capillarity in the Sn/graphite system

Aiming to investigate the role of wettability in the infiltration of tin into graphite particle compacts, sessile drop and infiltration experiments have been carried out at temperatures in the range of 300–700 °C. The surface tension of liquid tin and the contact angle at the tin/graphite interface have been measured in an argon atmosphere by means of the sessile drop technique, while pressure infiltration of Sn into compacts of graphite particles (27.2 μm of average diameter) has been carried out in air. The results indicate that the threshold pressure for infiltration is proportional to the work of immersion, as predicted by the capillary law. The particle geometric factor derived from the slope of the straight line is similar to that obtained previously from infiltration of aluminum. Although these results may indicate that the oxide layer that covers the tin surface plays a minor role in the infiltration process, a definitive conclusion may require a more detailed analysis of this interesting system.