INTRODUCTION

Definitions and Concepts

Materials science and engineering is a multidisciplinary activity that has emerged in recognizable form only during the past two decades. Practitioners in the field develop and work with materials that are used to make things—products like machines, devices, and structures. More specifically:

Materials science and engineering is concerned with the generation and application of knowledge relating the composition, structure, and processing of materials to their properties and uses.

The multidisciplinary nature of materials science and engineering is evident in the educational backgrounds of the half-million scientists and engineers who, in varying degree, are working in the field. Only about 50,000 of them hold materials-designated degrees;* the rest are largely chemists, physicists, and nonmaterials-designated engineers. Many of these professionals still identify with their original disciplines rather than with the materials community. They are served by some 35 national societies and often must belong to several to cover their

*  

We define a “materials-designated degree” as one containing in its title the name of a material or a material process or the word “material.” Examples include metallurgy, ceramics, polymer science or engineering, welding engineering, and materials science or engineering. Thus far, virtually all materials-designated degrees are in matallurgy or ceramics.



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Materials and Man's Needs: Materials Science and Engineering INTRODUCTION Definitions and Concepts Materials science and engineering is a multidisciplinary activity that has emerged in recognizable form only during the past two decades. Practitioners in the field develop and work with materials that are used to make things—products like machines, devices, and structures. More specifically: Materials science and engineering is concerned with the generation and application of knowledge relating the composition, structure, and processing of materials to their properties and uses. The multidisciplinary nature of materials science and engineering is evident in the educational backgrounds of the half-million scientists and engineers who, in varying degree, are working in the field. Only about 50,000 of them hold materials-designated degrees;* the rest are largely chemists, physicists, and nonmaterials-designated engineers. Many of these professionals still identify with their original disciplines rather than with the materials community. They are served by some 35 national societies and often must belong to several to cover their *   We define a “materials-designated degree” as one containing in its title the name of a material or a material process or the word “material.” Examples include metallurgy, ceramics, polymer science or engineering, welding engineering, and materials science or engineering. Thus far, virtually all materials-designated degrees are in matallurgy or ceramics.

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Materials and Man's Needs: Materials Science and Engineering professional and technical needs. This situation is changing, if slowly. One recent indication was the formation of the Federation of Materials Societies, in 1972. Of the 17 broadly based societies invited to join, nine had done so by October 1973. Materials are exceptionally diverse. The scope of materials science and engineering spans metals, ceramics, semiconductors, dielectrics, glasses, polymers, and natural substances like wood, fibers, sand, and stone. For our purposes we exclude certain substances that in other contexts might be called “materials.” Typical of these are foods, drugs, water, and fossil fuels. Materials as we define them have come increasingly to be classified by their function as well as by their nature; hence, biomedical materials, electronic materials, structural materials. This blurring of the traditional classifications reflects in part our growing, if still imperfect, ability to custom-make materials for specific functions. The Nature of Materials Materials, energy, and the environment are closely interrelated. Materials are basic to manufacturing and service technologies, to national security, and to national and international economies. The housewife has seen her kitchen transformed by progress in materials: vinyl polymers in flooring; stainless steel in sinks; Pyroceram and Teflon in cookware. The ordinary telephone contains in its not-so-ordinary components 42 of the 92 naturally occurring elements. Polyethylene, an outstanding insulator for radar equipment, is but one of the myriad materials vital to national defense. By one of several possible reckonings, production and forming of materials account for some 20

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Materials and Man's Needs: Materials Science and Engineering percent of the nation’s gross national product, but the number is deceptive; without materials we would have no gross national product. Man tends to be conscious of products and what he can do with them, but also tends to take the materials in products for granted. Nylon is known far better in stockings than as the polyamide engineering material used to make small parts for automobiles. The transistor is known far better as an electronic device, or as a pocket-size radio, than as the semiconducting material used in the device and its many relatives. Some materials produce effects out of proportion to their cost or extent of use in a given application. Synthetic fibers, in the form of easy-care clothing, have worked startling changes in the lives of housewives. Certain phosphor crystals, products of years of research on materials that emit light when bombarded by electrons, provide color-television pictures at a cost of less than 0.5 percent of the manufacturing cost of the set. The properties of specific materials often determine whether a product will work. In manned space flights, ablative materials of modest cost are essential to the performance of the heat shield on atmospheric reentry vehicles. New or sharply improved materials are critical to progress in energy generation and distribution. At the other extreme are home-building materials, whose properties, though important, need not be markedly improved to meet society’s goals in housing. Materials commonly serve a range of technologies and tend to be less proprietary than are the products made of them. Materials,

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Materials and Man's Needs: Materials Science and Engineering as a result, are likely to offer more fruitful ground for research and development, including cooperative research and development, than are specific products. One example is certain “textured” materials, polycrystalline structures in which the alignment of neighboring crystals is determined by the processing steps employed. The ability thus to control crystal orientation grew out of research by physicists, metallurgists, and even mathematicians. The resulting improvements in properties are proving useful in a widening spectrum of applications. They include soft magnetic alloys for memory devices, oriented steels for transformers, high-elasticity phosphor bronze for electrical connectors, and steel sheet for automobile fenders, appliance housings, and other parts formed by deep drawing. The Total Materials Cycle All materials move in a “total materials cycle” (Frontispiece), which in this report we will simply call the “materials cycle,” From the earth and its atmosphere man takes ores, hydrocarbons, wood, oxygen, and other substances in crude form and extracts, refines, purifies, and converts them into simple metals, chemicals, and other basic raw materials. He modifies these raw materials to alloys, ceramics, electronic materials, polymers, composites, and other compositions to meet performance requirements; from the modified materials he makes shapes or parts for assembly into products. The product, when its useful life is ended, returns to the earth or the atmosphere as waste. Or it may be dismantled to recover basic materials that reenter the cycle. The materials cycle is a global system whose operation includes strong three-way interactions among materials, the environment, and

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Materials and Man's Needs: Materials Science and Engineering energy supply and demand. The condition of the environment depends in large degree on how carefully man moves materials through the cycle, at each stage of which impacts occur. Materials traversing the cycle may represent an investment of energy in the sense that the energy expended to extract a metal from ore, for example, need not be expended again if the metal is recycled. Thus a pound of usable iron can be recovered from scrap at about 20 percent of the “energy cost” of extracting a pound of iron from ore. For copper the figure is about 5 percent, for magnesium about 1.5 percent. Materials scientists and engineers work most commonly in that part of the materials cycle that extends from raw materials through dismantling and recycling of basic materials. Events in this (or any other) area typically will have repercussions elsewhere in the cycle or system. Research and development, therefore, can open new and sometimes surprising paths around the cycle with concomitant effects on energy and the environment. The development of a magnetically levitated transportation system could increase considerably the demand for the metals that might be used in the necessary superconducting or magnetic alloys. Widespread use of nuclear power could alter sharply the consumption patterns of fossil fuels and the related pressures on transportation systems. The materials cycle can be perturbed in addition by external factors such as legislation. The Clean Air Act of 1970, for example, created a strong new demand for platinum for use in automotive exhaust-cleanup catalysts. The demand may be temporary, since catalysis has been questioned as the best long-term solution to the problem, but

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Materials and Man's Needs: Materials Science and Engineering whatever platinum is required will have to be imported, in large measure, in the face of a serious trade deficit. Environmental legislation also will require extensive recovery of sulfur from fuels and from smelter and stack gases; by the end of the century, the tonnage recovered annually could be twice the domestic demand. Such repercussions leave little doubt of the need to approach the materials cycle systematically and with caution. The Materials Revolution Man historically has employed materials more or less readily available from nature. For centuries he has converted many of them, first by accident and then empirically, to papyrus, glasses, alloys, and other functional states. But in the few decades since about 1900, he has learned increasingly to create radically new materials. Progress in organic polymers for plastics and rubbers, in semiconductors for electronics devices, in strong, light-weight alloys for structural use has bred entire industries and accelerated the growth of others. Engineers and designers have grown steadily more confident that new materials somehow can be developed, or old ones modified, to meet unusual requirements. Such expectations in the main have been justified, but there are important exceptions. It is by no means certain, for example, that materials can be devised to withstand the intense heat and radiation that would be involved in a power plant based on thermonuclear fusion, although the fusion reaction itself is not primarily a materials problem. This expanding ability to create radically new materials stems largely from the explosive growth that has occurred during this century

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Materials and Man's Needs: Materials Science and Engineering in our scientific understanding of matter. Advances in knowledge also have contributed much to the unifying ideas of materials science and engineering—wave mechanics, phase transitions, structure/property relationships, dislocation theory, and other concepts that apply to many classes of traditionally “different” materials. Certain semiconductor materials are perhaps the archetypal example of the conversion of fundamental knowledge to materials that meet exacting specifications. Our basic understanding of most materials, however, falls short of the level required to design for new uses and environments without considerable experimental effort. Hence, it is important to keep adding to the store of fundamental knowledge through research, although much empirical optimization will probably always be needed to deal with the complex substances of commerce. The Systems Concept Thorough systems analysis has been used to a moderate extent in materials science and engineering, but it must become basic to the field in view of the complexity of modern materials problems and of the fact that the materials cycle itself is a vast system. The need for the systems approach is apparent in the ramifications of replacing copper wire with aluminum in many communications uses in which the substitution would not have worked well until a few years ago. The move was triggered by changing relative prices and supply conditions of the metals. A research and development program produced aluminum alloys with the optimum combination of mechanical and electrical properties. The aluminum wire still had to be somewhat larger in diameter than copper wire, however. Thus wire-drawing machines had to be redesigned, in part

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Materials and Man's Needs: Materials Science and Engineering to avoid residual strain in the aluminum wire. Thicker wire, in addition, requires larger conduits, which take more space. And new joining techniques were necessary to avoid corrosion mechanisms peculiar to the aluminum wire. Products like nuclear reactors, jet engines, and integrated circuits (Figures 1, 2, 3) are systems of highly interdependent materials, each carefully adapted to its role in the total structure. The reaction of such a system to a breakdown at one point is evident in the intended use of a promising graphite-epoxy composite for the compressor blades of a British engine for an American jet airliner. The material was not developed on schedule, to the required degree of service reliability. The repercussions reached well beyond the resulting redesign of the engine. The respective governments were compelled to extricate both companies involved from financial crises, in an atmosphere of sharp debate over domestic and foreign policy. Materials in a Changing Context Materials and the associated science and engineering exist in a social and economic context that has changed markedly in the past five years. A pertinent indicator is the National Colloquy on Materials Science and Engineering, held in April 1969; the proceedings* took virtually no notice of the field’s close ties to the environment, an omission that could hardly occur today. Materials are involved also in *   Materials Science and Engineering in the United States, Rustum Roy, Ed., Pennsylvania State University Press, University Park, Pa., 1970.

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Materials and Man's Needs: Materials Science and Engineering FIGURE 1. Materials in a Boiling-Water Nuclear Reactor Materials shown here in a conventional boiling-water reactor for producing electric power evolved over years of development. A problem for the future is the perfection of nuclear-fuel assemblies for a commercial breeder reactor. The uranium dioxide fuel pellets used in the boiling-water reactor will probably be replaced by uranium-plutonium dioxide pellets. Working out the relevant characteristics of the new fuel will occupy many scientists and engineers for several years. (Illustration courtesy of General Electric Company)

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Materials and Man's Needs: Materials Science and Engineering FIGURE 2. Materials in a Jet Engine Materials complexity is evident in the jet engine, where an overriding goal is to improve the ratio of thrust to weight. Materials with good potential for the purpose are composites. Carbon- or boron-reinforced polymers, for example, might replace the titanium-aluminum-vanadium alloy used in the low-temperature fan blades (top left). (Illustration courtesy of General Electric Company)

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Materials and Man's Needs: Materials Science and Engineering FIGURE 3. Materials in an Integrated Circuit Among the unusual requirements for semiconducting materials in integrated circuitry and other solid-state electronic devices is the precise processing control of composition and structure in large-scale commercial production of assemblies measured in hundredths and even thousandths of an inch. (Illustration courtesy of Texas Instruments, Inc.)

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Materials and Man's Needs: Materials Science and Engineering other kinds of change: the nation’s problems with the balance of trade, federal efforts to stimulate and to assess technology; changing patterns in spending on basic and applied research and between civilian-oriented and defense- or space-oriented research and development; and the growing federal awareness of the importance of materials. Two fundamental parameters in these matters are population growth and higher incomes. Between 1900 and 1970, the population of the United States rose 270 percent, to just under 205 million. For the year 2000 the Bureau of the Census projects a minimum population of 251 million and a maximum of 300 million. Per-capita gross national product in constant 1958 dollars, meanwhile, has risen steadily, from $1,351 in 1909 to $3,572 in 1971. Both population and per-capita gross national product are expected to continue to grow, making ever more urgent the solution of materials-related problems. Energy, Environment The emergence of energy as a national problem of the first rank was reflected in mid-1973 in the President’s establishment of a White House Energy Policy Office and his call for drastically increased federal spending on energy research and development. At the same time the President asked Congress to authorize a Cabinet-level Department of Energy and Natural Resources and the splitting of the Atomic Energy Commission into an Energy Research and Development Administration and a Nuclear Energy Commission. The energy problem also is reflected in the formation of the Electric Power Research Institute by public and private utilities that account for about 80 percent of the nation’s generating capacity. The Institute will supervise research and

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Materials and Man's Needs: Materials Science and Engineering development for the electric utility industry and plans to spend some $100 million in 1974, its first year of full operation. The Institute will be funded by self-assessment of member companies and also will seek to work with the federal government and equipment manufacturers. National concern for the environment has been recognized in the past few years by extensive federal legislation and by the creation of the Environmental Protection Agency and the Council on Environmental Quality. Environmental matters achieved international status with the Stockholm Conference on the Human Environment, held in mid-1972 under the aegis of the United Nations General Assembly. The status was formalized in December 1972 when the General Assembly established a new unit, the U.N. Environmental Programme. The U.S. Trade Balance Materials are important factors in this country’s balance of trade. The National Commission on Materials Policy has reported that, in 1972, the United States imported $14 billion worth of minerals (including petroleum) and exported $8 billion worth, for a net deficit of $6 billion. If the trends of the past 20 years persist, the Commission said, the deficit could top $100 billion annually by the year 2000. In 1970, the United States imported all its primary supplies of chromite, columbium, mica, rutile, tantalum, and tin; more than 90 percent of its aluminum, antimony, cobalt, manganese, and platinum; more than half of its asbestos, beryl, cadmium, fluorspar, nickel, and zinc; and more than a third of its iron ore, lead, and mercury. Certain science-intensive materials, on the other hand, including organic chemicals

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Materials and Man's Needs: Materials Science and Engineering and plastics and resins, have produced, consistently, a positive balance of trade (Table 1). The country’s balance of trade has suffered from growing imports of manufactured products (Table 1). This has happened particularly with low-technology (experience-intensive) goods and, to a lesser extent, with high-technology (science-intensive) goods (even allowing for a degree of controversy over which is which). It appears, in fact, that the United States lost its technological leadership in some product areas, although cause-and-effect relationships among research and development budgets, technological initiative, and foreign trade are difficult to establish clearly (and lie, in any case, beyond the competence of COSMAT). The federal government has initiated modest efforts to stimulate civilian research, development, and innovation, so as to help recover technological initiative (which may have been lost, for example, in steel and titanium). The goal is to make U.S. products more competitive at home and abroad, and much of the emphasis will be on manufacturing technology, including materials shaping, forming, assembly, and finishing. The federal efforts include the Experimental Technology Incentives Program of the National Bureau of Standards in the Department of Commerce and the Experimental R&D Incentives Program of the National Science Foundation. Technology Assessment Technology assessment has long been practiced, in varying degree, in both industry and government, but a formal federal apparatus was established only recently by the Technology Assessment Act of 1972.

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Materials and Man's Needs: Materials Science and Engineering TABLE 1 U.S. Trade Balance in Illustrative Product Categories   (millions) 1960 1965 1970 Aircraft and Parts $1,187 $1,226 $2,771 Electronic Computers and Parts 44 219 1,044 Organic Chemicals 228 509 715 Plastic Materials and Resins 304 384 530 Scientific Instruments and Parts 109 245 407 Air Conditioning and Refrigeration Equipment 135 207 374 Medical and Pharmaceutical Products 191 198 333 Rubber Manufacture 108 119 –28 Textile Machinery 104 54 –37 Copper Metal –62 –132 –171 Phonographs and Sound Reproduction 15 –36 –301 Paper and Paper Products –501 –481 –464 Footwear –138 –151 –619 TV’s and Radios –66 –163 –717 Iron and Steel 163 –605 –762 Petroleum Products –120 –464 –852 Textiles and Apparel –392 –757 –1,542 Automotive Products 642 972 –2,039   Source: U.S. Department of Commerce.

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Materials and Man's Needs: Materials Science and Engineering The Office of Technology Assessment and other mechanisms created by the Act are designed to give the Congress a stronger in-house grasp of the relative merits and side effects of alternative technologies. The Act did not establish a formal technology-assessment function in the Executive Branch. The birth of the Office of Technology Assessment appears nevertheless to be stimulating similar efforts in various parts of the Executive Branch. Trends in Basic and Applied Research The relative economic austerity of the past few years has been felt in basic and applied research in both industry and government. Nonfederal spending on research and development has virtually leveled off (in constant dollars), while federal spending has been declining (Figure 4). In current dollars, total federal spending on research and development has been rising slowly since 1970, but the emphasis has been shifting away from defense and space toward civilian-oriented areas (Figure 5). Expenditures on space have been falling, while spending on domestic programs has been rising slightly faster than on defense research and development (although starting from a much smaller base). In constant dollars, federal spending on both basic and applied research leveled off in the late 1960’s; more recently, spending on basic research has declined slightly, while that on applied research has risen slightly (Figure 6). The Federal Approach to Materials The federal government has not yet developed a comprehensive national policy on materials. Materials-related responsibilities are

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Materials and Man's Needs: Materials Science and Engineering FIGURE 4 RESEARCH AND DEVELOPMENT SPENDING IN THE UNITED STATES 1953–72 AVERAGE ANNUAL RATE OF GROWTH % YEAR CURRENT $ CONSTANT $ TOTAL FEDERAL NON-FEDERAL TOTAL FEDERAL NON-FEDERAL 1953–61 13.7 16.3 10.1 11.3 13.9 7.8 1961–67 8.4 7.7 9.7 6.3 5.6 7.5 1967–72 3.4 1.0 6.8 –1.0 –3.3 2.3 SOURCE: NATIONAL SCIENCE FOUNDATION (1972)

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Materials and Man's Needs: Materials Science and Engineering FIGURE 5 CONDUCT OF FEDERAL RESEARCH AND DEVELOPMENT (OBLIGATIONS CURRENT DOLLARS) SOURCE: OFFICE OF SCIENCE AND TECHNOLOGY (1972)

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Materials and Man's Needs: Materials Science and Engineering FIGURE 6 TRENDS IN FEDERAL BASIC AND APPLIED RESEARCH SOURCE: NATIONAL SCIENCE FOUNDATION (1972)

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Materials and Man's Needs: Materials Science and Engineering diffused among a variety of formal and ad hoc committees and advisory groups, such as the Interagency Council for Materials. The government is assisted also by groups like the National Materials Advisory Board and the Committee on Solid State Sciences in the National Research Council. The gradual emergence of a more coherent federal approach to materials questions, however, would appear to be implicit in certain developments of the past few years. The Resource Recovery Act of 1970 created a National Commission on Materials Policy, whose charge was “to enhance environmental quality and conserve materials by developing a national materials policy to utilize present resources and technology more efficiently, to anticipate the future materials requirements of the nation and the world, and to make recommendations on the supply, use, recovery, and disposal of materials.” The Commission reported to the President and to the Congress in June 1973. The Mining and Minerals Policy Act of 1970 requires the Department of the Interior to make annual reports and recommendations for action in relation to a national minerals policy. The Second Annual Report under this Act was published in June 1973. The creation of a Materials Research Division in the National Science Foundation brought into clearer focus the existence of a multi-disciplinary materials-research community. Finally, recent years have seen considerable interest in the idea that the earth’s finite content of resources for industrial materials (including fuels) restricts severely the industrial growth

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Materials and Man's Needs: Materials Science and Engineering that traditionally has been considered the basis of economic and societal health.* This concept of “limits to growth,” and the related idea of a “steady-state society,” are not within the scope of this study. They are, however, further indications of the changing context in which materials science and engineering exists and in which, we believe, the field has useful contributions to make. *   See, for example, H.Brooks, “Materials in a Steady State World,” Metallurgical Transactions, 3, 759 (1972).