The Scheil Equation

Many materials are manufactured by solidification, either as a final product by casting, or as an intermediate ingot or bar. The Scheil equation describes the partitioning that takes place during solidification and the resulting spatial redistribution of solute, which makes it difficult to maintain a homogeneous material composition, and which leads to unwanted concentrations of harmful impurities. This chapter explains nucleation and growth processes during solidification, the resulting dendritic, faceted, equiaxed and columnar structures depending on thermal conditions and material type, coupled solidification of two-phase eutectic materials, and typical casting methods and associated structures and defects. Very little is known about Erich Scheil, who worked at the Max Planck Institute in Stuttgart in the mid-20th century.