Eutectic Solidification Processing

Eutectic Solidification Processing: Crystalline and Glassy Alloys deals with solidification theory and its application to eutectic processing of crystalline and glassy alloys. The underlying theme is an analysis of the different paths taken by the liquid-solid transformation as the cooling rate increases and a description of the structure and properties of the solid formed, ranging from equilibrium to metastable phase formation in castings, to metallic glass formation in splat quenched ribbons. This text has seven chapters; the first of which describes the main characteristics of the liquid-solid transformation. The chapters that follow show how control over composition, trace impurities, heat flow and cooling rate, and nucleation and growth gives rise to a wide range of solidification structures. Models of the nucleation and growth of eutectic and primary phases are analyzed and used to explain how cast microstructures are formed. Aluminum casting alloys and all types of cast iron are discussed, along with primary phase formation, the dependence of the extent of segregation on solidification conditions, and the practice of segregation prevention during solidification. This book also describes the importance of fluid flow in producing macroscopic segregation in large ingots and considers ways of minimizing this defect. Finally, this book gives a brief account of the various types of metallic glasses, their fabrication, important properties, and potential applications. This book will be of interest to materials scientists and industrial materials engineers.

1 The Liquid-Solid Transformation in Alloys Close to the Eutectic Composition

Introduction

Thermodynamic Criterion for Liquid-Solid Equilibrium in a Metal

The Liquid-Solid Transformation in a Metal

Thermodynamic Criterion for Equilibrium in Alloys

The Liquid-Solid Transformation in an Alloy

Diffusionless Solidification

The Liquid-Glass Transformation in Alloys

Metastable-Phase Formation in the Liquid-Solid Transformation

References

2 The Eutectic Solidification Process

Introduction

Nucleation in Eutectic Solidification

Homogeneous Nucleation

Heterogeneous Nucleation

Nucleation and Characteristics of a Eutectic Grain

The Grain Structure of a Casting

References

3 Growth in Normal Eutectic Solidification

Introduction

The Steady-State Lamellar Growth Problem

The Jackson and Hunt Analysis

Experimental Observations during Lamellar Growth

Other Features of the Jackson and Hunt Theory

Assessment of the Jackson and Hunt Analysis

The Analysis of Lamellar Growth

References

4 Growth in Anomalous Eutectic Solidification

Introduction

Criterion for Faceting during Growth

The Classification of Eutectic Microstructures

Anomalous Structures

References

5 Aluminum-Silicon Alloys and Cast Irons: Commercially Important Anomalous Alloys

Introduction

Aluminum-Silicon Eutectic Structures

Types and Properties of Aluminum Alloys

Types and Properties of Cast Iron

References

6 Primary-Phase Solidification in Alloys Close to the Eutectic Composition

Introduction

Faceted Primary-Phase Morphologies

Non-Faceted Primary-Phase Morphology

The Brody-Flemings Model of a Dendritic Array

Developments of the Brody-Flemings Model

Alternative Models of the Dendritic Array

The Influence of Fluid Flow on Solidification

The Coupled Zone

Monotectic Solidification

References

7 Production, Properties and Uses of In-Situ Composites and Metallic Glasses

Production of In-Situ Composites

Tensile Behavior of In-Situ Composites

Creep Behavior of In-Situ Composites

Fatigue Behavior of In-Situ Composites

Microstructural Stability of In-Situ Composites

The Production of Metastable Structures and Metallic Glasses

The Properties and Uses of Metallic Glasses

References

Index