Fundamentals of Creep in Metals and Alloys


Book Description

* Numerous line drawings with consistent format and units allow easy comparison of the behavior of a very wide range of materials * Transmission electron micrographs provide a direct insight in the basic microstructure of metals deforming at high temperatures * Extensive literature review of over 1000 references provide an excellent reference document, and a very balanced discussionUnderstanding the strength of materials at a range of temperatures is critically important to a huge number of researchers and practitioners from a wide range of fields and industry sectors including metallurgists, industrial designers, aerospace R&D personnel, and structural engineers. The most up-to date and comprehensive book in the field, Fundamentals of Creep in Metals and Alloys discusses the fundamentals of time-dependent plasticity or creep plasticity in metals, alloys and metallic compounds. This is the first book of its kind that provides broad coverage of a range of materials not just a sub-group such as metallic compounds, superalloys or crystals. As such it presents the most balanced view of creep for all materials scientists. The theory of all of these phenomena are extensively reviewed and analysed in view of an extensive bibliography that includes the most recent publications in the field. All sections of the book have undergone extensive peer review and therefore the reader can be sure they have access to the most up-to-date research, fully interrogated, from the world's leading investigators.· Numerous line drawings with consistent format and units allow easy comparison of the behavior of a very wide range of materials· Transmission electron micrographs provide a direct insight in the basic microstructure of metals deforming at high temperatures· Extensive literature review of over 1000 references provide an excellent reference document, and a very balanced discussion




High Temperature Oxidation and Corrosion of Metals


Book Description

The book is concerned with understanding the fundamental mechanisms of high temperature alloy oxidation. It uses this understanding to develop methods of predicting oxidation rates and the way they change with temperature, gas chemistry and alloy composition. The focus is on designing (or selecting) alloy compositions which provide optimal resistance to attack by corrosive gases. . Emphasises quantitative calculations for predicting reaction rates and the effects of temperature, oxidant activities and alloy compositions. . Uses phase diagrams and diffusion paths to analyse and interpret scale structures and internal precipitation distributions . Provides a detailed examination of corrosion in industrial gases (water vapour effects, carburisation and metal dusting, sulphidation) . Text is well supported by numerous micrographs, phase diagrams and tabulations of relevant thermodynamic and kinetic data . Combines physical chemistry and materials science methodologies.




Creep and High Temperature Deformation of Metals and Alloys


Book Description

By the late 1940s, and since then, the continuous development of dislocation theories have provided the basis for correlating the macroscopic time-dependent deformation of metals and alloys—known as creep—to the time-dependent processes taking place within the metals and alloys. High-temperature deformation and stress relaxation effects have also been explained and modeled on similar bases. The knowledge of high-temperature deformation as well as its modeling in conventional or unconventional situations is becoming clearer year by year, with new contemporary and better performing high-temperature materials being constantly produced and investigated. This book includes recent contributions covering relevant topics and materials in the field in an innovative way. In the first section, contributions are related to the general description of creep deformation, damage, and ductility, while in the second section, innovative testing techniques of creep deformation are presented. The third section deals with creep in the presence of complex loading/temperature changes and environmental effects, while the last section focuses on material microstructure–creep correlations for specific material classes. The quality and potential of specific materials and microstructures, testing conditions, and modeling as addressed by specific contributions will surely inspire scientists and technicians in their own innovative approaches and studies on creep and high-temperature deformation.




High Temperature Strain of Metals and Alloys


Book Description

Creep and fatigue are the most prevalent causes of rupture in superalloys, which are important materials for industrial usage, e.g. in engines and turbine blades in aerospace or in energy producing industries. As temperature increases, atom mobility becomes appreciable, affecting a number of metal and alloy properties. It is thus vital to find new characterization methods that allow an understanding of the fundamental physics of creep in these materials as well as in pure metals. Here, the author shows how new in situ X-ray investigations and transmission electron microscope studies lead to novel explanations of high-temperature deformation and creep in pure metals, solid solutions and superalloys. This unique approach is the first to find unequivocal and quantitative expressions for the macroscopic deformation rate by means of three groups of parameters: substructural characteristics, physical material constants and external conditions. Creep strength of the studied up-to-date single crystal superalloys is greatly increased over conventional polycrystalline superalloys. From the contents: - Macroscopic characteristics of strain at high temperatures - Experimental equipment and technique of in situ X-ray investigations - Experimental data and structural parameters in deformed metals - Subboundaries as dislocation sources and obstacles - The physical mechanism of creep and the quantitative structural model - Simulation of the parameters evolution - System of differential equations - High-temperature deformation of industrial superalloys - Single crystals of superalloys - Effect of composition, orientation and temperature on properties - Creep of some refractory metals For materials scientists, solid state physicists, solid state chemists, researchers and practitioners from industry sectors including metallurgical, mechanical, chemical and structural engineers.




Development of High-temperature Strain Gages


Book Description

A summary is presented of a research program aimed at the improvement of high-temperature strain gages of the electrical resistance type. Potential ceramic and metal components were evaluated and a gage was devised that was based on these evaluations. This gage (NBS 5B) was flexible and easy to install; however, it lacked resistance stability at higher temperatures. In an attempt to minimize this deficiency, ceramic cements were developed that showed greater electrical resistivity than had been previously observed in the range 800 to 1800 degrees Fahrenheit; also, a technique was devised for increasing the resistance to ground by applying a fired-on ceramic coating to the grid of a specifically developed unbacked gage. A study was made of the cause of the erratic response of cemented gages that had not been preheated prior to use. There were strong indications that the erratic response was caused mostly by the rapid decrease in resistance that accompanied structural changes in the cement.




Yield Point Phenomena in Metals and Alloys


Book Description

Exceptions to the rule are always interesting, and the anomalies in the stress-strain curves of mild steel and in many other metals and alloys have excited the curiosity of engineers and scientists for well over a hundred years. Yet it is only during the last twenty years that significant theoretical advances have been made, and the aim of this book has been to examine these theories against the background of the considerable volume of experimental results published over the last few years, up to mid-1969. Hence this review volume has a two-fold aim; the first chapter attempts to review the general theories of yield point phenomena, using sufficient examples only to illustrate the theories. This chapter is intended to be complete in itself, and could be read by under graduates who wish to appraise rapidly the general background to the problem. The remaining chapters deal, in turn, with the various alloys exhibiting yield point phenomena. Thus, chapter 2 on mild steel, is a more extensive study of quench and strain ageing, while Chapter 3 is on the refractory metals and discusses theories of the low-temperature strength. The next concerns hydrogen in meta-Is. Chapters 5 and 6 discuss the face-centred cubic alloys, particularly the cases of the unloading yield point and intermetallic compounds. Chapter 7 covers hexagonal and ionic structures. A brief final chapter considers the areas where further research may be fruitful.




Mechanical Properties and Working of Metals and Alloys


Book Description

This book is intended to serve as core text or handy reference on two key areas of metallic materials: (i) mechanical behavior and properties evaluated by mechanical testing; and (ii) different types of metal working or forming operations to produce useful shapes. The book consists of 16 chapters which are divided into two parts. The first part contains nine chapters which describe tension (including elastic stress – strain relation, relevant theory of plasticity, and strengthening methods), compression, hardness, bending, torsion – pure shear, impact loading, creep and stress rupture, fatigue, and fracture. The second part is composed of seven chapters and covers fundamentals of mechanical working, forging, rolling, extrusion, drawing of flat strip, round bar, and tube, deep drawing, and high-energy rate forming. The book comprises an exhaustive description of mechanical properties evaluated by testing of metals and metal working in sufficient depth and with reasonably wide coverage. The book is written in an easy-to-understand manner and includes many solved problems. More than 150 numerical problems and many multiple choice questions as exercise along with their answers have also been provided. The mathematical analyses are well elaborated without skipping any intermediate steps. Slab method of analysis or free-body equilibrium approach is used for the analytical treatment of mechanical working processes. For hot working processes, different frictional conditions (sliding, sticking and mixed sticking–sliding) have been considered to estimate the deformation loads. In addition to the slab method of analysis, this book also contains slip-line field theory, its application to the static system, and the steady state motion, Further, this book includes upper-bound theorem, and upper-bound solutions for indentation, compression, extrusion and strip drawing. The book can be used to teach graduate and undergraduate courses offered to students of mechanical, aerospace, production, manufacturing and metallurgical engineering disciplines. The book can also be used for metallurgists and practicing engineers in industry and development courses in the metallurgy and metallic manufacturing industries.




Fracture at High Temperatures


Book Description




Failure Mechanisms in Alloys


Book Description

The era of lean production and excellence in manufacturing, advancing with sustainable development, demands the rational utilization of raw materials and energy resources, adopting cleaner and environmentally-friendly industrial processes. In view of the new industrial revolution, through digital transformation, the exploitation of smart and sophisticated materials systems, the need of minimizing scrap and increasing efficiency, reliability and lifetime and, on the other hand, the pursuit of fuel economy and limitation of carbon footprint, are necessary conditions for the imminent growth in a highly competitive economy. Failure analysis is an interdisciplinary scientific topic, reflecting the opinions and interpretations coming from a systematic evidence-gathering procedure, embracing various important sectors, imparting knowledge, and substantiating improvement practices. The deep understanding of material/component role (e.g., rotating shaft, extrusion die, gas pipeline) and properties will be of central importance for fitness for purpose in certain industrial processes and applications. Finally, it is hoped and strongly believed that the accumulation of additional knowledge in the field of failure mechanisms and the adoption of the principles, philosophy, and deep understanding of failure analysis process approach will strongly promote the learning concept, as a continuously evolving process leading to personal and social progress and prosperity.




Materials for High Temperature Engineering Applications


Book Description

This concise survey describes the requirements on materials operating in high-temperature environments and the processes that increase the temperature capability of metals, ceramics, and composites. The major part deals with the applicable materials and their specific properties, with one entire chapter devoted to coatings. Written for engineering and science students, researchers, and managers in industry.