ABSTRACT
This chapter considers some cases relating to metallic and ceramic systems. These include Liquid (L) + two primary solid solutions (α and β) giving a three phase eutectic reaction L → α + β; Liquid (L) + two primary solid solutions (α and β) giving a three-phase peritectic reaction L + α → β; and Transition between eutectic and peritectic reactions. The chapter also considers a hypothetical system ABC in which it is assumed that there is complete liquid miscibility. Binary system AC shows complete solid solubility, while systems AB and BC show partial solubility and are of the eutectic type. The solid solutions are termed α and β respectively. The three-phase space is associated with the eutectic reaction L → α + β which occurs over a range of temperature in a ternary system, not at a constant temperature as in a binary system. The three-phase region may be considered as being made up of a stack of isothermal tie-triangles.
