Electromagnetic levitation: In-situ diagnostics of non-equilibrium solidification of undercooled melts

The electromagnetic leviation technique is applied for undercooling of bulk melts of metallic alloys. Large degrees of undercooling become accessible by avoiding heterogeneous nucleation on container walls and processing the melt under high purity conditions. This article reviews various in-situ diagnostic methods such as the capacitance proximity sensor technique, high-speed videometry and in-situ X-ray diffraction using synchrotron radiation to study non-equilibrium solidification phenomena in undercooled melts. Experimental results on metastable phase formation and rapid solidification determined with high accuracy are used to verify theories for nucleation and dendritic growth.