Introduction to equilibrium S.J.T.U. Phase Transformation and Applications The concept of equilibrium is fundamental Stable,unchanging with time and certain properties of the system are uniform throughout The system may not be homogeneous in form -Co-existence of ice and water ·Phase A portion of matter that is uniform throughout,not only in chemical composition,but also in physical state The usefulness of many metallic,polymeric,and ceramic systems depends on the presence,at equilibrium,of various different phases in the material SJTU Thermodynamics of Materials Spring2006©X.J.Jin Lecture 7 equilibrium IPhase Transformation and Applications S. J. T. U. SJTU Thermodynamics of Materials Spring 2006 © X. J. Jin Lecture 7 equilibrium I Introduction to equilibrium • The concept of equilibrium is fundamental • Stable, unchanging with time and certain properties of the system are uniform throughout • The system may not be homogeneous in form – Co-existence of ice and water • Phase – A portion of matter that is uniform throughout, not only in chemical composition, but also in physical state – The usefulness of many metallic, polymeric, and ceramic systems depends on the presence, at equilibrium, of various different phases in the material