The interior of an arc casting furnace is shown. Arc casting has been employed for many years at ISU and Ames Laboratory, for preparing alloys and inter-metallic compounds for materials research.
The molten metal in the center is zirconium, #40 on the periodic table. It has a melting point of 3,371°F (1,855°C). It is held on a copper hearth, copper melts at 1,984°F (1,085°C)! Why doesn't the Zr melt through the Cu? Answer: copper has a very high thermal conductivity. the Cu mold is water cooled from below, which keeps the Cu from melting." by Trevor Riedemann
via ISU Photostream