Engineering Materials Science

Milton Ohring

• Publisher: Academic Press
• Year: 1995
• ISBN:
  9780080505695
• Topic: Physical Sciences
• Subtopic: Physics
• Index: Physics

Milton Ohring's Engineering Materials Science integrates the scientific nature and modern applications of all classes of engineering materials. This comprehensive, introductory textbook will provide undergraduate engineering students with the fundamental background needed to understand the science of structure-property relationships, as well as address the engineering concerns of materials selection in design, processing materials into useful products, andhow material degrade and fail in service. Specific topics include: physical and electronic structure; thermodynamics and kinetics; processing; mechanical, electrical, magnetic, and optical properties; degradation; and failure and reliability. The book offers superior coverage of electrical, optical, and magnetic materials than competing text.The author has taught introductory courses in material science and engineering both in academia and industry (AT&T Bell Laboratories) and has also written the well-received book, The Material Science of Thin Films (Academic Press).Key Features* Provides a modern treatment of materials exposing the interrelated themes of structure, properties, processing, and performance* Includes an interactive, computationally oriented, computer disk containing nine modules dealing with structure, phase diagrams, diffusion, and mechanical and electronic properties* Fundamentals are stressed* Of particular interest to students, researchers, and professionals in the field of electronic engineering

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INTRODUCTION TO MATERIALS SCIENCE AND ENGINEERING

1.1 MATERIALS RESOURCES AND THEIR IMPLICATIONS

1.1.1 A Historical Perspective

The designation of successive historical epochs as the Stone, Copper, Bronze, and Iron Ages reflects the importance of materials to mankind. Human destiny and materials resources have been inextricably intertwined since the dawn of history; however, the association of a given material with the age or era that it defines is not only limited to antiquity. The present nuclear and information ages owe their existences to the exploitation of two remarkable elements, uranium and silicon, respectively. Even though modern materials ages are extremely time compressed relative to the ancient metal ages they share a number of common attributes. For one thing, these ages tended to define sharply the material limits of human existence. Stone, copper, bronze, and iron meant successively higher standards of living through new or improved agricultural tools, food vessels, and weapons. Passage from one age to another was (and is) frequently accompanied by revolutionary, rather than evolutionary, changes in technological endeavors.

It is instructive to appreciate some additional characteristics and implications of these materials ages. For example, imagine that time is frozen at 1500 BC and we focus on the Middle East, perhaps the world’s most intensively excavated region with respect to archaeological remains. In Asia Minor (Turkey) the ancient Hittites were already experimenting with iron, while close by to the east in Mesopotamia (Iraq), the Bronze Age was in flower. To the immediate north in Europe, the south in Palestine, and the west in Egypt, peoples were enjoying the benefits of the Copper and Early Bronze Ages. Halfway around the world to the east, the Chinese had already melted iron and demonstrated a remarkable genius for bronze, a copper–tin alloy that is stronger and easier to cast than pure copper. Further to the west on the Iberian Peninsula (Spain and Portugal), the Chalcolithic period, an overlapping Stone and Copper Age held sway, and in North Africa survivals of the Late Stone Age were in evidence. Across the Atlantic Ocean the peoples of the Americas had not yet discovered bronze, but like others around the globe, they fashioned beautiful work in gold, silver, and copper, which were found in nature in the free state (i.e., not combined in oxide, sulfide, or other ores).

Why materials resources and the skills to work them were so inequitably distributed cannot be addressed here. Clearly, very little technological information diffused or was shared among peoples. Actually, it could not have been otherwise because the working of metals (as well as ceramics) was very much an art that was limited not only by availability of resources, but also by cultural forces. It was indeed a tragedy for the Native Americans, still in the Stone Age three millennia later, when the white man arrived from Europe armed with steel (a hard, strong iron–carbon alloy) guns. These were too much of a match for the inferior stone, wood, and copper weapons arrayed against them. Conquest, colonization, and settlement were inevitable. And similar events have occurred elsewhere, at other times, throughout the world. Political expansion, commerce, and wars were frequently driven by the desire to control and exploit materials resources, and these continue unabated to the present day.

When the 20th century dawned the number of different materials controllably exploited had, surprisingly, not grown much beyond what was available 2000 years earlier. A notable exception was steel, which ushered in the Machine Age and revolutionized many facets of life. But then a period ensued in which there was an explosive increase in our understanding of the fundamental nature of materials. The result was the emergence of polymeric (plastic), nuclear, and electronic materials, new roles for metals and ceramics, and the development of reliable ways to process and manufacture useful products from them. Collectively, this modern Age of Materials has permeated the entire world and dwarfed the impact of previous ages.

Only two representative examples of a greater number scattered throughout the book will underscore the magnitude of advances made in materials within a historical context. In Fig. 1-1 the progress made in increasing the strength-to-density (or weight) ratio of materials is charted. Two implications of these advances have been improved aircraft design and energy savings in transportation systems. Less visible but no less significant improvements made in abrasive and cutting tool materials are shown in Fig. 1-2. The 100-fold tool cutting speed increase in this century has resulted in efficient machining and manufacturing processes that enable an abundance of goods to be produced at low cost. Together with the dramatic political and social changes in Asia and Europe and the emergence of interconnected global economies, the prospects are excellent that more people will enjoy the fruits of the earth’s materials resources than at any other time in history.

FIGURE 1-1 Chronological advances in the strength-to-density ratio of materials. Optimum safe load-bearing capacities of structures depend on the strength-to-density ratio. The emergence of aluminum and titanium alloys and, importantly, composites is responsible for the dramatic increase in the 20th century. Reprinted with permission from Materials Science and Engineering for the 1990s. Copyright 1989 by the National Academy of Sciences. Courtesy of the National Academy Press, Washington, D.C.

FIGURE 1-2 Increase in machining speed with the development over time of the indicated cutting tool materials. Adapted from M. Tesaki and H. Taniguchi, High speed cutting tools: Sintered and coated, Industrial Materials 32, 64 (1984).

1.1.2 The Materials Cycle

The United States has an enormous investment in the scientific and engineering exploitation of materials resources. A very good way to visualize the scope of this activity is to consider the total materials cycle shown in Fig. 1-3. The earth is the source of all resources that are mined, drilled for, grown, harvested, and so on. These virgin raw materi...

Table of contents

• Cover image
• Title page
• Table of Contents
• Inside Front Cover
• Copyright
• Dedication
• PREFACE
• ACKNOWLEDGMENTS
• Chapter 1: INTRODUCTION TO MATERIALS SCIENCE AND ENGINEERING
• Chapter 2: ELECTRONS IN ATOMS AND SOLIDS: BONDING
• Chapter 3: STRUCTURE OF SOLIDS
• Chapter 4: POLYMERS, GLASSES, CERAMICS, AND NONMETALLIC MIXTURES
• Chapter 5: THERMODYNAMICS OF SOLIDS
• Chapter 6: KINETICS OF MASS TRANSPORT AND PHASE TRANSFORMATIONS
• Chapter 7: MECHANICAL BEHAVIOR OF SOLIDS
• Chapter 8: MATERIALS PROCESSING AND FORMING OPERATIONS
• Chapter 9: HOW ENGINEERING MATERIALS ARE STRENGTHENED AND TOUGHENED
• Chapter 10: DEGRADATION AND FAILURE OF STRUCTURAL MATERIALS
• Chapter 11: ELECTRICAL PROPERTIES OF METALS, INSULATORS, AND DIELECTRICS
• Chapter 12: SEMICONDUCTOR MATERIALS AND DEVICES: SCIENCE AND TECHNOLOGY
• Chapter 13: OPTICAL PROPERTIES OF MATERIALS
• Chapter 14: MAGNETIC PROPERTIES OF MATERIALS
• Chapter 15: FAILURE AND RELIABILITY OF ELECTRONIC MATERIALS AND DEVICES
• APPENDIX A: PROPERTIES OF SELECTED ELEMENTS (AT 20°C)
• APPENDIX B: VALUES OF SELECTED PHYSICAL CONSTANTS
• APPENDIX C: CONVERSION FACTORS
• ANSWERS TO SELECTED PROBLEMS
• INDEX
• DOCUMENTATION FOR ENGINEERING MATERIALS SCIENCE COMPUTER MODULES