Chapter 11 Component elements or compounds that are mixed initially Phases homogenous physically distinct and mechanically separable portion of the material with a given chemical composition and structure Solution solid liquid or gas solution single phase Mixture more than one phase Solubility limit max concentration for which only a single phase solution exist Equilibrium when free energy is at a minimum given at a specified combination of T P and composition Phase diagrams o Binary systems 2 components o Independent variables T and C isomorphous complete solubility of one component in another PD tells us about the melting casting crystallization The microstructure depends on Alloying elements Concentration Heat treatment temperature time rate of cooling Eutectic eutectic mixture mixture of two or more phases at a composition that has the lowest melting point o It is where the phases simultaneously crystallize from molten solution o These diagrams on next sheet Isothermal means it s a reversible reaction Eutectic liquid transforms to two solid phases Eutectoid one solid phase transforms to two other solid phases Peritectic liquid and one solid phase transform to a 2nd solid phase