The Theory of Transformations in Metals and Alloys

General Introduction. Classification of transformations. Characteristics of nucleation and growth transformations. Characteristics of martenistic transformations. Isothermal transformation curves

Formal Geometry of Crystal Lattices. Description of the ideal crystal. Linear transformations of the coordinate system. Affine transformations: homogeneous deformation. twin crystals.

The Theory of Reaction Rates. Chemical kinetics and activation energy. The reaction rate theory.

The Thermodynamics of Irreversable Processes. Microscopical reversability: the onsager reciprocal relations. Entropy production in natural processes.

The Structure of Real Metals. Metallic structures: polymorphism. Point defects in crystals. Crystal surfaces: the equilibrium structure of a step. The structure of close-packed surfaces.

Solids Solutions. Pair probablility functions: thermodynamic properties. The nearest neighbour model: regular solutions. The quasi-chemical theory: other statistical theories. Misfit energy in solid solutions: sub-regular solutions.

The Theory of Dislocations. Introduction: edge and screw dislocations. Geometrical properties of dislocations. Dislocations in an elastic medium. Formation and properties of crystal dislocations

Polycrystalline Aggregates. Macroscopic theory. Dislocation models of grain boundaries. Grain boundary energies. Interphase boundaries: surface dislocations.

Diffusion in the Solid State. Mechanism of atomic migration. Statistical basis of diffusion: Fick's law. Phenomenological theory of diffusion. Uphil diffusion.

The Classical Theory of Nucleation. The formation of nuclei of a new phase. Heterophase fluctuations: Volmer's theory of nucleation. The Becker-Döring theory of nucleation. Nucleation of the solid from the vapour of the liquid.

Theory of Thermally Activated Growth. Growth controlled by processes at the interface. Diffusion-controlled growth. Linear growth of duplex regions.

Formal Theory of Transformation Kinetics. Transformation nucleated on grain boundaries. Analysis of isothermal transformation curves. Transformation with parabolic growth laws. Effects of temperature: non-isothermal transformations.

Part II

Growth from the Vapour Phase. Growth of a perfect crystal at low supersaturation. Real crystals: Frank's theory of crystal growth. The growth of surface coatings and thin films from the vapour. Growth of whiskers, nanocrystals, quasi-crystals and amorphous solids from the vapour phase.

Solidification and Melting.The solidification of pure metals. Nucleation of the liquid-solid change in alloys. The growth of crystals from the melt. Growth from a liquid alloy.

Polymorphic Changes. Solid-state reactions in pure metals. Massive transformations.

Precipitation from Supersaturated Solid Solution. Types of precipitation: spinodal decomposition. Continuous precipitation. Discontinuous precipitation. GP zone formation and other low temperature changes.

Eutectoidal Transformations.Eutectoidal decomposition and T-T-T diagrams. The austenite-pearlite transformation in steels. The formation of austenite from two-place mixtures of ferrite and cementite.

Order-Disorder Transformations. The formation of superlattice. Ordering as a continuous reaction: changes in long-range order.

Recovery Recrystalisation and Grain Growth. Anealing of cold-worked metals. Primary recrystallization. Grain growth, secondary recrystallization and twin formation.

Deformation Twinning. Crystallography of twinning. Operative twinning modes in metallic structures. Nucleation and growth of mechanical twins. Effects of external variables on twinning.

Characteristics of Martensic Transformations. Atomic movements in the transformation. Deformation produced by moving interfaces. Effects of stress: thermoelastic transformation.

Crystallography of Martensitic Transformations. General description of formal theories. The martenistic transformation in steels. Body-centered cubic to orthorhombic transformations. Other applications of the formal theory.

Kinetics of Martensitic Transformations. The nucleation of martensite. Formal kinetics of martensite formation.

Rapid Solidification. Methods for rapid cooling of a liquid: general properties of resultant solid. Amorphous (glassy) metals. Quasi-crystals.

Bainite Steels. Microstructures and properties. Crystallography of bainite.

Shape Memory Alloys. Pseudo-elasticity and hysteresis. Shape memory.