There is currently great interest in the process of diffusion bonding. The main thrust has been in the joining of advanced materials such as superplastic alloys, metal matrix composites and ceramics and, most importantly, to introduce the process into mass-production operations. Diffusion bonding has also led to reduced manufacturing costs and weight savings in conventional materials and developments in hot isostatic pressing have allowed greater design flexibility. Since the first conference on Diffusion Bonding, held at Cranfield in 1987, considerable advances have been made and it was therefore considered appropriate to organise the Second International Conference on Diffusion Bonding which was held at Cranfield Institute of Technology on 28 and 29 March 1990. The meeting provided a forum for the presentation and discussion of recent developments in Diffusion Bonding and was divided into four main subject areas: steel bonding and quality control, diffusion bonding of aluminium alloys, bonding of high temperature materials and general applications. This structure is retained in the proceedings. DAVID STEPHENSON vii CONTENTS v Preface ......................... .

The book emphasizes various aspects of processing secondary sources for recovery of uranium. The field of secondary resource processing is gaining ground over the last few years as it is eco-friendly, economical and in tune with the philosophy of sustainable development. The book is the first one of its type in the area and includes a succint and comprehensive description of related areas of ore mineralogy, resource classification, processing principles involved in uranium solubilisation followed by separation and safety aspects. The clear organisation and the carefully selected figures and tables makes the treatment invaluable for practising engineers, research workers and academic institutions.

Includes science and technology of processing solid minerals to concentrates of grades, suitable for industrial extraction of metal values and other non-metallic products Provides a logical progression from basic to advanced concepts in mineral processing Designed to stimulate students to think as mineral processing engineers in training Explores sustainable mineral processing and circular economy in mineral processing Contains worked examples that clearly illustrates the various theories presented and help readers develop problem solving skills in mineral processing

An understanding ofthe properties and the handling characteristics of liquids and gases has long been regarded as an essential requirement for most practising engineers. It is therefore not surprising that, over the years, there has been a regular appearance of books dealing with the fundamentals of fluid mechanics, fluid flow, hydraulics and related topics. What is surprising is that there has been no parallel development of the related discipline of Bulk Solids Handling, despite its increasing importance in modern industry across the world. It is only very recently that a structured approach to the teaching, and learning, of the subject has begun to evolve. A reason for the slow emergence of Bulk Solids Handling as an accepted topic of study in academic courses on mechanical, agricultural, chemical, mining and civil engineering is perhaps that the practice is so often taken for granted. Certainly the variety of materials being handled in bulk is almost endless, ranging in size from fine dust to rocks, in value from refuse to gold, and in temperature from deep-frozen peas to near-molten metal.

Significant experimental work is devoted to the preparation of one and zero dimensional semiconductor structures in view of future electronic and optical devices which involve quantum effects. The aim is good control in the realisation of nanometer structures both in vertical and lateral direction. Conventional processing techniques based on lithography face inherent problems such as limited resolution and surface defects caused by reactive ion etching. During the last few years several research groups started working on direct syntheses of semiconductor nanostructures by combining epitaxial growth techniques such as molecular beam epitaxy and chemical vapour deposition with pre patterning of the substrate wafers. Another idea is based on island formation in strained layer heteroepitaxy. Zero and one dimensional structures with dimensions down to a few atomic distances have been realised this way. An important point is that the size of the quantum structures is controlled within the epitaxial deposition in a self-adjusting process. The main subjects of the book are: Theoretical aspects of epitaxial growth, selfassembling nanostructures and cluster formation, epitaxial growth in tilted and non-(001) surfaces, cleaved edge overgrowth, nanostructure growth on patterned silicon substrates, nanostructures prepared by selective area epitaxy or growth on patterned substrates, in-situ etching and device applications based on epitaxial regrowth on patterned substrates. The experimental work mainly concentrated on GaAs/A1GaAs, GaAs/InGaAs, InGaP/InP and Si/SiGe based semiconductor heterostructures. Growth related problems received special attention. The different concepts for preparation of low dimensional structures are presented to allow direct comparison and to identify new concepts for future research work.

teacher Professor Ernst-Joachim Ivers to whom I still owe many insights 20 years after the end of his working life. This English edition is not an unedited translation of the German edition of 1990. The text has been substantially revised in some chapters, taking into account the literature published in the mean time. I wish to thank Dr.-Ing. H. Finken, Freiberg, who has prepared the translation from German into English with deep scientific understanding and in close contact with the author. I also wish to express my gratitude to Chapman & Hall for their support to this project without which the English edition could not have been published. Dr.-Ing. habil. C. Bernhardt Freiberg 1 Position, tasks and structure of particle size analysis Today the concept of particle size analysis is that of a special field of particle measurement technology, which in turn is part of particulate technology. This classification has developed over the last 20 years; it is the result of a scientific integration process taking place in many industrialized countries of the world. In recent years, the meaning and mutual connection of the related concepts as well as the tasks of the scientific disciplines designated by them have been the subject of intensive discussion which, however, has not led to a generally accepted terminology.

In recent years the importance of extruded alloys has increased due to the decline in copper extrusion, increased use in structural applications, environmental impact and reduced energy consumption. There have also been huge technical advances. This text provides comprehensive coverage of the metallurgical, mathematical and practical features of the process.

100 years after the first observation of ripening by Ostwald and 40 years after the first publication of a theory describing this process, this monograph presents, in a self-consistent and comprehensive manner, all the bits and pieces of coarsening theories so that the main issues and the underlying mathematics of self-similar coarsening of dispersed systems can be understood. It contains all of the background material necessary to understand growth and coarsening of spherical particles or droplets in a liquid or solid matrix. Some basic knowledge of heat and mass transfer, thermodynamics and differential equations would be helpful, but not necessary, as all the concepts required are introduced. The text is suitable for advanced undergraduate and graduate students as well as for researchers. Rather than giving a complete survey of the field, it presents a careful derivation of the existing results and places them into some perspective.

This thesis consists of an in-depth study of investigating microstructure-property relationships in bulk metallic glasses using a novel quantitative approach by which influence of the second phase features on mechanical properties can be independently and systematically analyzed. The author evaluates and optimizes the elastic and plastic deformation, as well as the overall toughness of cellular honeycombs under in-plane compression and porous heterostructures under uniaxial tension. The study reveals three major deformation zones in cellular metallic glass structures, where deformation changes from collective buckling showing non-linear elasticity to localized failure exhibiting a brittle-like deformation, and finally to global sudden failure with negligible plasticity as the length to thickness ratio of the ligaments increases. The author found that spacing and size of the pores, the pore configuration within the matrix, and the overall width of the sample determines the extent of deformation, where the optimized values are attained for pore diameter to spacing ratio of one with AB type pore stacking.

Emerging Fields in Sol-gel Science and Technology contains selected papers from the symposium on "Sol-Gel and Vitreous Materials and Applications" held during the International Materials Research Congress in Cancun, Mexico in August 2002. One hundred and twenty researchers representing 10 countries attended this symposium.

Some of the subjects covered in this symposium include 1.) synthesis of new materials endowed with outstanding and non-conventional optical, magnetic, electrical, thermal, catalytic, and mechanical properties; 2.) study of the sorption properties of model porous materials in order to test the validity of previous and recent theories; 3.) theoretical studies related to density functional theory, fractal and scaling law approaches, 4.) synthesis of biomaterials for use in medicine and pollution control; 5.) application of sol-gel colloids in the fine-chemistry industry in products such as fragrances and pharmaceuticals; 6.) development of special vitreous materials; 7.) implementation of inorganic thin films, and 8.) synthesis of materials for energy saving. "

Hailed instantly as the definitive field reference, the first edition of Metallurgical Failures in Fossil Fired Boilers provided a comprehensive catalog of the types of metallurgical failures common to boilers. Using actual case histories of boiler shutdowns, the book documented, as no existing text did, the full range of causes of boiler tube failure - providing a blueprint for cutting maintenance costs and upgrading the efficiency and reliability of any power plant operation. Reflecting the heightened focus throughout the industry on boiler-tube failure analysis, this expanded Second Edition sheds light on the latest innovative insights and solutions highlighting the field. The new edition now features material on fluid dynamics, heat transfer, and stress calculations, essential requirements of boiler design. For added relevance, this edition includes important information on making material-condition and end-of-life assessments for plant equipment being used beyond its original design expectations. Also included is up-to-date information on the higher temperature ranges now experienced by boilers. An expanded listing of boiler equipment as well as new case studies examining an even wider, more current range of problems makes the book more useful than ever. Yet, the Second Edition retains the structure and practical tone of its successful forerunner. Readers will again find detailed and expert analysis of the full range of metallurgical failures common to boilers - from corrosion, high-temperature related phenomena, welding problems, fabrication defects, to changes in microstructure, oxidation, exfoliation, decarburization, and more. Specific real-world examples of each of the causesof failure are provided, along with full operating details of the particular unit at the time of rupture. In addition, the fundamentals of elementary metallurgy are clearly presented, enabling even non metallurgists to fully grasp the analyses of the examples given. Not only is the significance of metallurgy in boiler design made clear, the new updated edition also illustrates the key mechanical engineering aspects of the design process as well. Underscoring, with practical specifics, the importance of preventative design techniques, the Second Edition is an incomparable handbook to building more failure-resistant boiler and heat-transfer equipment. Basic to the maintenance and success of any power plant operation in the 1990s, Metallurgical Failures in Fossil Fired Boilers, Second Edition is destined to become the undisputed staple of the professional's library or drafting board.

The attractive physical and mechanical properties of ordered intermetallic alloys have been recognized since early in this century. However, periodic attempts to develop intermetallics for structural applications were unsuc cessful, due in major part to the twin handicaps of inadequate low-temper ature ductility or toughness, together with poor elevated-temperature creep strength. The discovery, in 1979, by Aoki and Izumi in Japan that small additions of boron caused a dramatic improvement in the ductility of Ni3Al was a major factor in launching a new wave of fundamental and applied research on intermetallics. Another important factor was the issuance in 1984 of a National Materials Advisory Board reported entitled "Structural Uses for Ductile Ordered Alloys," which identified numerous potential defense-related applications and proposed the launching of a coordinated development program to gather engineering property and processing data. A substantial research effort on titanium aluminides was already underway at the Air Force Materials Laboratory at Wright Patterson Air Force Base in Ohio and, with Air Force support, at several industrial and university laboratories. Smaller programs also were under way at Oak Ridge National Laboratory, under Department of Energy sponsorship. These research efforts were soon augmented in the United States by funding from Department of Defense agencies such as Office of Naval Research and Air Force Office of Scientific Research, and by the National Science Foundation."

For a long time the die cast industry has used trial and error as a development method, resulting in tremendous growth in the utilization of available CFD (computational fluid dynamics) software. This book will refresh knowledge of the governing laws of the fluid dymanics that have an effect on die cast die and die cast process design.

The Biomaterials Science and Engineering Series is designed to help stimulate further developments in biomaterials science and engineering by disseminating up-to-the-minute, quality information to academic and industrial research and development scientists employed in all areas of the medical, biomedical and bioengineering sciences whether in medical device R&D, pharmaceutical and pharmacological research or materials science, and to clinical specialists in prosthetics and surgery.

Contrary to popular belief, the future for metals and alloys as biomaterials is strong. State-of-the-art engineering methods, combined with the intrinsic strengths of metals, have resulted in considerably improved and new types of medical device. This timely reference provides a detailed appraisal of:

• biomaterial selection, with emphasis on mechanical strength, fatigue resistance and fracture toughness

• the inherent shortcomings of metals and how best to deal with them

• shape memory alloys

• surface treatment, thin organic coatings, and polymer—metal macrocomposites

• tissue—implant interactions and biocompatibility

• x-ray photoelectron spectroscopy and electrochemical impedance spectroscopy

Mechanical Alloying is intended as an introduction to the mechanical alloying technique used in developing different materials systems. It is useful not only to undergraduate and post-graduate students, but also to scientists and engineers who wish to gain some understanding of the process. Mechanical Alloying begins with a brief introduction providing a historical background to the development of the mechanical alloying process. Currently there are several different types of ball mills available, some of them specially designed for the mechanical alloying process. Since the resultant materials are milling-intensity and milling-temperature dependent, ball mills should be carefully selected in order to obtain the desired materials and structures. This is discussed in Chapter 2. The actual mechanical alloying process is considered in Chapter 3. As it is essential to understand the use of processing control agents, the physical properties of some commonly used agents are listed. Chapter 4 deals with the formation of new materials and presents the mechanical alloying of Al, Ti and Mg alloys and their intermetallics. The formation of composite materials using this technique is also discussed in detail. Several examples of the mechanical alloying of amorphous materials, an important group of engineering materials where mechanical alloying is commonly employed, are given. Chapter 5 looks at the characterization of the alloyed powders. Details of the use of X-ray diffraction to identify crystalline size, the use of thermal analysis and measurement of particle size are provided. Densification methods are discussed in Chapter 6 while mechanisms of strengthening the composite materials bymechanical alloying are considered in Chapter 7. To understand the mechanisms of the alloying technique so that better control of the process can be exercised, the effects of temperature, activation energy, and grain size on diffusion during the alloying process are examined in Chapter 8. The last chapter of the book, Chapter 9, deals with the dynamics and modeling of the alloying process together with some experimental outputs.

The aim of this book is to present a rigorous phenomenological and mathematical formulation of sedimentation processes and to show how this theory can be applied to the design and control of continuous thickeners. The book is directed to stu dents and researchers in applied mathematics and engineering sciences, especially in metallurgical, chemical, mechanical and civil engineering, and to practicing en gineers in the process industries. Such a vast and diverse audience should read this book differently. For this reason we have organized the chapters in such a way that the book can be read in two ways. Engineers and engineering students will find a rigorous formulation of the mathematical model of sedimentation and the exact and approximate solutions for the most important problems encountered in the laboratory and in industry in Chapters 1 to 3, 7 and 8, and 10 to 12, which form a self-contained subject. They can skip Chapters 4 to 6 and 9, which are most important to applied mathematicians, without losing the main features of sedimentation processes. On the other hand, applied mathematicians will find special interest in Chapters 4 to 6 and 9 which show some known but many recent results in the field of conservation laws of quasilinear hyperbolic and degenerate parabolic equations of great interest today. These two approaches to the theory keep their own styles: the mathematical approach with theorems and proofs, and the phenomenological approach with its deductive technique."

This book introduces the principles of the response of steels to the austenitizing process and is intended to act as a source book for information and review purposes for metallurgists, metallurgical engineers and other materials scientists.