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Materials and Man’s Needs Materials Science and Engineering: Volume II The Needs, Priorities, and Opportunities for Materials Research CHAPTER 4 NATIONAL OBJECTIVES AND THE ROLE OF MATERIALS SCIENCE AND ENGINEERING* * This chapter is based primarily on the work of Hans H.Landsberg and Roland W.Schmitt of COSMAT Panel VI and on inputs from several of their colleagues on COSMAT and at the General Electric Company.
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Materials and Man’s Needs Materials Science and Engineering: Volume II The Needs, Priorities, and Opportunities for Materials Research This page in the original is blank.
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Materials and Man’s Needs Materials Science and Engineering: Volume II The Needs, Priorities, and Opportunities for Materials Research CHAPTER 4 NATIONAL OBJECTIVES AND THE ROLE OF MATERIALS SCIENCE AND ENGINEERING INTRODUCTION The Nature of National Goals There are different kinds of national goals. Some are ultimate objectives of society and are as old as the Constitution and its amendments. These goals define the kind of society we try to be, but they are not, as a rule, reducible to tasks for science and engineering. “Life, liberty, and the pursuit of happiness” are objectives that can be and are advanced by achievements in science and technology, but one would find it hard to derive from them specific programs in MSE. We may call them aspirations, principles, concepts, ideals, or goals, if we like. Below this towering top comes a layer of other comprehensive national goals that embraces and defines areas of endeavor. Provision of free education for all is an old one; free medical care for the aged a more recent one While subject to change in detail, these are nonetheless continuing objectives, but, in any hierarchy of goals, they still lie above those that are more directly related to technological or materials tasks. Moreover, one does well to think of a wide spectrum of kinds of goals as well as of a ranking. Various types of goals in the science and technology field alone are, for example— Large, discrete tasks of social utility (e.g., model cities, urban mass-transportation systems) Complex, open-ended programs (e.g., weather prediction, oceanographic program) Large research tasks, with likely social utility (e.g., Apollo, Mohole) Large fundamental research tasks of uncertain outcome but great social utility (e.g., nuclear fusion, nuclear propulsion) Correction of social deficiencies (e.g., poverty, genetic defects) Improvement of productive performance (e.g., reduction in mortality, increased man-hour productivity)
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Materials and Man’s Needs Materials Science and Engineering: Volume II The Needs, Priorities, and Opportunities for Materials Research Specific inventions (e.g., aircraft-noise suppressor, alternative to internal combustion engine) etc. etc. Similar diversity exists along other classes of goals, i.e., one can distinguish between social goals, goals of scientific understanding, goals associated with pragmatic application of knowledge, and surely others. Anyone searching for a repository of national goals or anything approaching it will be disappointed. Some goals are so persistent and fundamental that they are built into the conscience of the nation and of every citizen. The various “freedoms,” both from and to, are of that kind. Others are implied in the structure of American society. Easing of upward social mobility, for example, would be hard to identify in any piece of legislation, yet it is undoubtedly a pervasive goal. So is increased man-hour productivity. These are canons by which we live and act. As one leaves the loftier goals and focuses more on the recent past, it becomes easier to identify specifically formulated goals; this is largely because they cannot be taken for granted, are not “self-evident,” but arise out of changing perceptions, as crystallization of widely-felt needs, as responses to events, or sometimes as “brainchildren” of illustrious citizens. In short, as the level of aggregation drops, the degree of specificity increases. As a result, one can ascertain and assert more forcefully that a goal does in fact exist, and one can more easily link the likelihood of its achievement to activities in MSE. A useful distinction can be made between goals that have been formulated at some level of government—usually at the federal level—and are embedded in a piece of legislation, an Executive Order, a regulation, and those that rest on a less conspicuous basis, yet partake of the nature of national goals. The “conquest of polio” as compared with the “conquest of cancer” serves to illustrate the difference. The latter is an organized and specifically financed societal goal embedded in a federal statute. The fight against polio, supported financially largely by the annual “March of Dimes,” undoubtedly was as much the expression of national desire, but its implementation was diffuse, unstructured, and left to individual initiative and excellence. In the category of the less articulate, an interesting national goal and of significance to MSE is one that might be called “economic strength.” While there exists a whole fabric or arsenal of laws designed to facilitate the smooth functioning of the economy (to strengthen competition, safeguard the sanctity of contracts, minimize labor disputes, encourage inventiveness, etc., etc.) one can point only to a single piece of legislation that sets up “economic strength or (disregarding recent misgivings as to its validity) “growth” as a national goal. That legislation was the Employment Act of 1946, which was aimed at establishing “maximum employment, production and purchasing power” as a national goal, or as a trinity of goals. Only once in recent times has there been a governmental attempt to formulate specific national goals as guides to policy. That was under the Eisenhower Administration, when it adopted the recommendations of the Presidential Commission on National Goals. A different approach was taken by President Nixon when he set up in the Executive Office a “goals research staff” intended to be a permanent feature but disbanded after it had
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Materials and Man’s Needs Materials Science and Engineering: Volume II The Needs, Priorities, and Opportunities for Materials Research rendered its first report to the nation. The chapters of that report, issued July 4, 1970, are entitled “Population Growth and Distribution,” “Environment,” “Education,” “Basic National Science,” “Technology Assessment,” “Consumerism,” “Economic Choice and Balanced Growth,” and “Toward Balanced Growth.” Obviously, these are not goals. Rather, the topics suggest that in the process of selection, the Staff tried to determine in what areas conflicts would in the future have to be resolved, objectives established, and debates carried on. Given the difficulty of defining goals and finding documentary support, the multiplicity of types of goals, their changing nature and stress, and COSMAT’s reluctance to consider itself appropriately composed for conducting an exercise in determining comprehensively what the nation’s goals seem to be, we have chosen a more modest way for evaluating the relationship between goals and MSE. We have selected some areas of national concern that affect all citizens in their daily lives and some that affect the nation’s fate as a whole, and have endeavored to show how needed advances can be assisted by contributions from MSE. We have concentrated on areas where (a) the materials aspect is, if not critical, at least obvious, (b) the contributions that materials advances might make are more easily demonstrated. Change is also a characteristic of the goals of interest to the materials community: change in the priorities among goals and changing emphasis within each. Changing priorities show up clearly when we consider either federal funding alone, overall public spending, or expenditures as reflected in the Gross National Product. Trends within broad goals are discussed extensively in the balance of this chapter. Limiting our review of federal spending to the recent past, we can clearly identify a number of trends in the allocation of funds (see Table 4.1). Defense, space, and international affairs, in which grouping the first accounts for the lion’s share, declined from 62 percent in 1955 to 37 percent in 1972, though absolute amounts for the same period rose from 42 to 86 billion (current) dollars. The relative decline was due mainly to the continuing and rapid rise in outlays aggregated under the generic term “Income Maintenance;” this item rose from 15 to 85 billion dollars over the same 17-year period and is now about equal to the defense/space/international affairs group in magnitude. Income maintenance comprises above all social security, welfare, and veterans pay, but also includes access to medical care and education. In relative terms, investment in human and physical resources has risen even more rapidly, as have housing and community development. There are important differences, however. For one thing, the absolute amounts involved are much smaller. Secondly, in the case of investment in physical resources (commerce, transportation, natural resources), growth has been discontinuous; a jump occurred in the second half of the 1950’s, and relative outlays have been on a plateau since. Thirdly, by way of contrast, in the case of housing and community development, the rise has been very recent. Only in the area of investment in human resources has there been a steady absolute as well as relative upward movement in federal spending, mostly in the field of education (Medicare outlays in this auditing scheme are carried under “income maintenance”). Federal outlays, of course, constitute only a portion of public spending. State and local government expenditures account for the balance. These have
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Materials and Man’s Needs Materials Science and Engineering: Volume II The Needs, Priorities, and Opportunities for Materials Research Table 4.1 Changes in Federal Budget Outlays,a 1950–1972, Selected Fiscal Years Category 1955 1960 1965 (Percent) 1970 1972 Defense, space, international 61.7 53.6 49.6 44.3 36.6 Income maintenance 22.0 26.7 29.0 32.4 36.2 Investment in human resourcesb 2.2 2.5 3.2 5.8 6.2 Investment in physical resourcesc 2.3 6.4 7.8 5.7 6.4 Housing and community development 0.7 0.8 1.0 2.7 3.5 Net interest on debt 6.9 7.5 7.3 7.3 6.2 Other 4.1 2.5 2.1 1.8 5.0 100 100 100 100 100 Source: Setting National Priorities—the 1972 Budget, Brookings Institution (1971) p. 13. a Not adjusted for sales of assets b Education, training, health c Commerce, transportation, natural resources
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Materials and Man’s Needs Materials Science and Engineering: Volume II The Needs, Priorities, and Opportunities for Materials Research risen more rapidly than federal funds: from not quite 40 billion (current) dollars in 1955 to 132 in 1969 (the most recent year for which published data permit these comparisons to be made). Put differently, state and local expenditures have advanced from 36 to 43 percent of total governmental expenditures between 1955 and 1969, with schools, highways, and welfare accounting for the bulk of state and local outlays. If one then aggregates public expenditures at all levels of government, it turns out that in 1969, defense and international affairs for instance, accounted for 27 percent (as against the more than 40 percent in the federal picture), and education for over 16 percent (compared to about 6 percent under the total “investment in human resources” item in the allocation of federal funds). Going beyond public spending, Table 4.2 presents society’s total expenditures in the 1960’s, cast in terms of specified national goals as patterned by a continuing study of the National Planning Association. Significant features of the presentation are the slower than average rise of national defense, agriculture, international aid, housing, and R&D. On the uptrend side are social welfare, education, transportation, health, natural resources, and private plant and equipment. By and large then, the picture parallels the one portrayed by the changes in public spending, except that all spending for housing is down, while governmental spending is up. The private consumption sector is of course a vast mix of incommensurables. To get closer to an understanding of its evolution in terms of materials, Table 4.3 presents a breakdown into three major categories. Perhaps the most interesting feature of Table 4.3 is the relatively rapid rise in expenditures for durables as compared with nondurables and services, though the increase in the last-named category precisely equals that of the entire group (and of GNP as a whole). It suggests that the trend toward services is not nearly as pronounced in private consumer expenditures as in the economy as a whole. With regard to goods, it does indicate that there has been much growth in precisely that segment of private consumption where materials can have their greatest impact: durable goods. A final comparison, before we draw some conclusions for the impact on the materials community of shifting public-expenditure trends, pertains to the relationship between the funding agency and the consumer of the result of funding. That is, in the case of defense and space outlays, the funder is at the same time the principal, if not the only, consumer of the product arising as the result of the funded expenditures. Such expenditures made, in other words, consitute close to 100 percent of the GNP for that function. In sharp contrast, federal transportation outlays represent only 6 to 7 percent of the output of the transportation industry, and still only 20 percent when state and local expenditures are included. In education and manpower, federal outlays represent a little over 10 percent of the GNP in that segment, but the percentage rises to nearly 90 when state and local expenditures are factored in. The corresponding figures in the health sector have recently run about 25 and 40 percent, respectively. They are lowest of all in housing; whether or not state and local expenditures are included, governmental outlays represent only about 6 percent of the output used.1 1 Data from Economic Report of the President, p. 101, 1970.
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Materials and Man’s Needs Materials Science and Engineering: Volume II The Needs, Priorities, and Opportunities for Materials Research Table 4.2 Expenditures for National Goals, 1962 and 1969 (in billions of 1969 dollars) Goal Area Expenditures in Percent Change, 1962 1969 1962 to 1969 Private consumption $418.5 $579.6 38.5% Private plant and equipment 62.0 98.6 59.0 Urban development 84.0 94.7 11.0 Housing 37.5 35.4 –5.5 Other urban facilities 46.5 59.3 13.0 National defense 66.5 78.8 18.5 Social welfare 46.4 71.1 53.0 Health 43.5 63.8 46.5 Education 41.8 64.3 54.0 Transportation 39.3 61.5 56.5 Research & development 21.1 26.9 27.5 Natural resources 7.1 10.1 42.0 Agriculture 8.2 7.8 –5.0 Environmental quality – 6.3 – International aid 6.1 5.3 –13.0 Manpower training 0.1 2.0 – GNP 678.0 931.4 37.5 Source: National Planning Association
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Materials and Man’s Needs Materials Science and Engineering: Volume II The Needs, Priorities, and Opportunities for Materials Research Table 4.3 Expenditures for Private Consumption, 1962 to 1969 (in billions of 1969 dollars) Expenditures in Percent Increase Category 1962 1969 1962 to 1969 Durable goods $52.0 $90.4 72.5 Nondurable goods 193.0 247.5 28.0 Services 174.5 242.0 38.5 All categories 418.5 579.6 38.5 Note: Details may not add to totals due to rounding Source: National Planning Association
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Materials and Man’s Needs Materials Science and Engineering: Volume II The Needs, Priorities, and Opportunities for Materials Research The above sketch suggests four major implications for the materials field. First, those segments of public spending that were prominent in funding R&D have suffered a relative decline. Second, the segment that has increased most in relative importance, i.e., income maintenance, has little direct linkage with materials. Third, those segments that have increased and do have an association with materials problems (housing, transport, etc.) account for only a minor share of the GNP generated in these sectors, i.e. whatever funding is performed will not, as compared with, say, defense, be directly translated into a ready market for the output. Fourth, the rising importance of state and local spending spells a shift to human resource development, prominently education (see above) and thus represents growth in an area in which so far at least materials have not played a key role. Given the enormous weight of “consumer expenditures” in the nation’s GNP, it is obvious that such inarticulate goals as durability, reliability, performance, safety, low-cost repairability, etc. pose a continuing challenge for MSE. Yet the play of the market is the only mechanism for coupling goals and materials, and as we have pointed out above, it functions far less directly than in areas where the purchaser has a very direct role in the specifications (defense, space etc.). One reason is that often the consumer cannot really specify what he wants, and if he does, his desires may not find a producer responding. In consumer areas, however, one must be careful not to confuse poor manufacturing practices with unsatisfactory material properties. Not know-what is achievable at reasonable cost, the consumer has a long list of desiderata but he cannot match it with potential solutions. All he can do is test different products offered and proceed by trial and error. Consumer choice is limited by the range of choice presented to him in the market place. Another poorly articulated goal, moving ever more forcefully onto center stage is materials substitution. Nobody and everybody has responsibility for it. The manufacturer will act on the basis of cost differentials, evaluated in terms of the firm’s profits. The consumer will act in equally narrow terms that include cost and convenience. Society’s interest that ranges from favoring materials with a longer-run supply potential to materials having less noxious environmental impact is basically an orphan, or we should say, has been until recently. In the future, one may expect greater emphasis on substitutions. These substitutions will be (a) the direct substitution of one material for another (aluminum for copper, nickel for silver, polyurethane for cork, etc.); (b) development of new ways to perform the same function (transmitting a telephone signal through transparent fibers in conjunction with light-emitting semiconductor diodes at the transmitting and semiconductor photodetector diodes at the receiving end, or substitution of integrated circuits for transistors and vacuum tubes, or development of wholly new adhesives); and (c) development of substitute technologies that could radically alter the patterns of materials demand (nuclear vs. fossil-fuel power generation, communication through solid-state electronics vs. transportation of people and goods). Constraints of various kinds will call for much more sophisticated approaches to substitution, and MSE is bound to play a major role in this sphere.
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Materials and Man’s Needs Materials Science and Engineering: Volume II The Needs, Priorities, and Opportunities for Materials Research In the balance of this chapter, we attempt to (a) specify some goals in the fields of communication networks, space, electrical power, transportation, health services, the environment, and housing, and then document their evolution by way of governmental pronouncements and actions in various contexts, and (b) illustrate how the achievement of these goals is connected with specific developments in MSE. The sectors chosen for reviewing the connection between materials research and national goals do not exhaust all segments of economic activity; nor do they cover the broader range that forms part of the materials research priority study described in the next chapter. Specifically, the subsequent discussion omits reference to what are broadly called consumer and producer durables. The reason is simply that one cannot identify anything there that could be regarded as a “national goal” beyond such very loose matters as “competitiveness,” “least-cost production,” etc. Nevertheless, these broad areas do present many important challenges to materials technology and some of these, in the area of defense, the supply of and demand for materials, and automation of industrial processes and methods, are briefly described. This chapter concludes with an overview of goal-oriented materials research opportunities and needs, many of which apply to several economic sectors. The Relevance-Tree Approach The approach to the identification of critical materials needs has generally been a “shredding out” of specific materials problems and tasks from the more broadly formulated goals; often referred to as the relevance-tree technique. For example, one may derive from the goal of abundant, reliable, low-cost, and environmentally acceptable electric power the route, among others, of controlled thermonuclear fusion and, by an extension of the process, the requirement of a material with specific tolerance for radiation damage. According to Jantsch2, technology transfer occurs vertically via at least eight levels. At each level, there can also be horizontal transfer. These are summarized in Tables 4.4 and 4.5 where some examples are also given. The eight levels represent progressively increasing (or decreasing) “levels of aggregation” —moving upwards in the tree involves embracing increasing breadth of techniques and technologies in order to achieve the desired social or economic objective. Vertical transfer can be up or down. When upwards, the science and engineering can be regarded as creative in that it creates new technologies, new functions, and new opportunities for society. When downwards, the science and engineering can be regarded as responsive in that it is responding to perceived societal needs. 2 E.Jantsch, Technological Forecasting in Perspective, O.E.C.D., Paris, 1967.
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Materials and Man’s Needs Materials Science and Engineering: Volume II The Needs, Priorities, and Opportunities for Materials Research thick. The estimated in-place cost, for a total of 12 buildings to justify the cost of production equipment, was comparable with conventional construction, partly because of reduced weight, reduced structural steel, reduced footings, and greatly increased speed of erection. This is an example of successful MSE that can occur when performance is set forth rather than prescriptive specifications. As building codes gradually evolve in the direction of performance rather than prescriptive codes, as enforcement agencies become sophisticated enough to handle such codes, and as designers become accustomed to thinking in terms of performance, it may be expected that composite uses of materials, as exemplified by the building sandwiches, will increase. It is to be noted, however, that the necessary social, economic, and political conditions must be present to allow such developments to occur. Encouragement of Innovation Innovative ideas, whether they relate to materials or other building components, have a hard time getting adopted partly because there is no accepted means of evaluating and certifying innovations. The individual with the bright new idea, no matter how good it may be, is faced with a long, arduous process for obtaining acceptance. There is, for example, no generally recognized testing agency. The innovators are faced with finding a university, private testing laboratory, or other organization to run tests. Even when this is done and the results are successful, the innovator is faced with the formidable task of convincing building code officials, architects, engineers, builders, financiers, and owners of the efficacy of his idea. It is no wonder, therefore, that unless he is exceptionally well financed, his idea may very well die before it has a chance to be tried. Some central agency, probably neither governmental nor completely private, is needed that has the expertise and the confidence of the building fraternity, to which an innovator can turn with his idea to have it examined, tests prescribed, evaluated, and certified as useful with whatever curbs and constraints may be necessary in the opinion of the agency. With this kind of certification, the innovator would have a much easier time in getting his idea tried. Examples exist in a number of European countries and have, in many cases, been notably successful. Whether the European counterparts should be adopted completely in the U.S. is, perhaps, problematical, but some kind of certification could be helpful in reducing the extremely difficult problem of gaining acceptance. Prediction of Behavior A major stumbling block to the adoption of new materials in the housing industry is the question of predicting long-time behavior on the basis of short-time tests. This is difficult, if not practically impossible in many cases, particularly for such critical problems as weathering. Completely reliable weathering tests which will satisfactorily predict the long-time
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Materials and Man’s Needs Materials Science and Engineering: Volume II The Needs, Priorities, and Opportunities for Materials Research behavior of materials are yet to be developed. This is a major technical issue and one which could well challenge the best efforts of materials scientists and engineers; it is a major deterrent to the adoption of new materials. Associated with the development of reliable testing methods is the need for the careful, comprehensive evaluation of existing installations. Although there is a good deal of scattered and relatively uncorrelated information regarding the behavior of materials and building components in actual service, a really systematic and thoroughly organized survey, readily available to all parts of the industry, does not exist. Evidently, this kind of information is basic, not only to the utilization of the existing materials, but to the prediction of the behavior of new materials and the development of tests. Fire Endurance The prediction of behavior of materials in building fires is in serious need of better understanding. Correlation between laboratory tests and actual building fires has to be greatly improved. Speed of ignition, rate of flamespread, smoke evolution, and penetration of fire through barriers such as walls and partitions are all measured by relatively empirical laboratory tests, but there is considerable doubt concerning the test results even though many of them are written into building codes for lack of something better. Most attention, until recently, has been focused on flame, flammability, flamespread, and flame penetration. Recently, partly because of the introduction of new materials, it has been realized that smoke evolution and the development of toxic or irritating gases may be more dangerous than actual flame in causing loss of life. The evolution of smoke and gases is even less well understood than the onset of flame. It is known that the same materials may behave quite differently in different kinds of fires, giving off dense smoke in some cases and practically none in others, depending upon temperature, oxygen availability, and still other factors. Here is another field where the transition should be made from empiricism and experience to a groundwork of scientific understanding, closely coupled with engineering application. NOTE ON NEEDS IN CONSUMER GOODS, PRODUCTION EQUIPMENT, AND AUTOMATION In addition to the preceding studies of the relations between MSE and various national goals, some less complete studies were made of the opportunities for materials R&D relating to consumer goods and production equipment. In connection with consumer goods, there is the persistent need for greater durability (both physical and chemical), less flammability, and greater safety, reliability, serviceability, and maintainability. A clear need exists also for better tests for these characteristics. Materials
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Materials and Man’s Needs Materials Science and Engineering: Volume II The Needs, Priorities, and Opportunities for Materials Research problems relevant to production equipment include longer-lasting, higher-speed machining devices, both metallic and ceramic (e.g., grinding wheels), better joining methods, and greater high-temperature strength. There are attractive opportunities in a special area of production equipment: automation and robotics. These opportunities exist not only in production and manufacturing, but also throughout the service areas of the economy—mail sorting, billing, typesetting, weather forecasting, health checkups, traffic control. Automation techniques in all of these directions include a common approach: the generation and processing of information to provide or display data in useful forms or to control servomechanisms. Myriad possibilities can be discerned in primary information-generating devices or sensors, which will depend on the nature of the physical property to be measured, the object to be sensed, or the pattern to be diagnosed. Nearly always these sensing techniques must be nondestructive. They must rely, therefore, on the effects of the interaction of matter with various kinds of radiation—optical, electromagnetic, ultrasonic, and others. Progress in this field clearly will require the most sophisticated knowledge of materials and of spectroscopy in its broadest sense. The signals generated by the primary sensing device usually must be processed, analyzed, and correlated by a computer or, increasingly, a mini-computer, itself a product of modern MSE in its integrated circuits and memory devices. Once in useful form, the information can be printed out, visually displayed, or used to control a machine or servomechanism. Prospects for improvement lie both in visual displays and in computer-controlled machines. The latter can range from simple mechanical transducers—to control a valve, for example—to complex robots that can simulate some of the routine actions of human beings. The development of this type of automation will require new devices, particularly optoelectronic, and solid-state electronic circuits with associative memory and learning capability for parallel processing. Especially promising avenues for further research appear to be semiconductor lasers and light-emitting diodes, magnetic-bubble devices, charge-coupled devices, reversible photosensitive materials, liquid crystals, optical modulators and deflectors, and various functional components such as amplifiers, timing circuits, and shift registers. Advances in servomechanism design will call for the combined talents of electrical and mechanical engineers, but often these devices and machines will also place stringent demands on the materials of which they are made, especially when the equipment must work reliably for long periods in hostile environments. Automation is a very broad interdisciplinary area and is likely to become more so. It embraces the knowledge and skills of materials scientists and engineers with those of the information community—mathematics and statisticians, as well as computer-hardware and software engineers. The economic and social implications of switching to automation in a given operation, moreover, can call also for the expertise of economists and social scientists.
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Materials and Man’s Needs Materials Science and Engineering: Volume II The Needs, Priorities, and Opportunities for Materials Research CHALLENGES IN THE MATERIALS CYCLE Today we are faced with growing competition for nonrenewable raw materials and fuels, as well as with low standards of living in much of the world. The latter is an old problem, but it is reemerging in a new setting that prominently features the aspirations of the developing countries, concern for the environment, and the scale of international human activities. These difficulties, in consequence, are attracting more and more attention, both in the U.S. and abroad, shifting to a degree the emphasis on national defense and political prestige toward more civilian-oriented goals and concerns. Materials science and engineering can help meet the technical challenges of these growing concerns. By providing options at the various stages in the materials cycle, it can exert direct, if not always immediately visible, effects in the problem areas reflected by national concerns. It can help to slow and sometimes to halt the growth in demand for certain raw materials and fuels. It can help to move hardware technologies in directions that raise living standards at home and abroad. It can help to reduce deleterious effects on the environment to acceptable levels. And it can help to achieve these goals in a manner consistent with a sound U.S. balance of trade. Exploration The sensing, information-processing, and transmitting functions of orbiting earth-resources satellites and lunar rovers were made possible by progress in development of electronic and structural materials. Comparable technology could be developed for exploring the ocean floor. For more traditional types of prospecting, instrumental methods should progress rapidly as more is learned of the “signatures” of complex natural materials. Mining Ores and minerals in the future probably will have to be mined in more hostile environments at less accessible sites. (Manganese and other metals, as well as phosphates, for example, are available on the ocean floor.) Working conditions often may be impossible for human operators. To tap the resources available from ultradeep mines or even below the ocean floor will require a new technology, “robotics.” In essence, robotics will involve solid-state electronic sensing and information-processing equipment coupled to servomechanical mechanisms that can operate under extreme conditions. The advent of novel equipment of this kind likewise will benefit conventional mining operations. Plasma and rocket-nozzle technology, for instance, has proved useful in drilling the hard, iron-bearing taconite—which has largely succeeded the heavily-depleted, high-grade domestic iron ore that was long the mainstay of the nation’s steel industry.
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Materials and Man’s Needs Materials Science and Engineering: Volume II The Needs, Priorities, and Opportunities for Materials Research Extraction We need very much to find new means of extracting basic materials from ores of progressively lower grade and from low-grade wastes, processes that are more efficient, that cost less, consume less energy, and cause less pollution. Aluminum already is being extracted from the abundant anorthosite (in the Soviet Union) as opposed to the conventional source, the high-grade but less plentiful bauxite. Under development in the U.S. are two new aluminum processes: one reduces by about a third the energy required to produce aluminum from alumina by electrolysis; the other produces aluminum in several (nonelectrolytic) steps, starting with various sources of the metal—not only bauxite, but low-grade alumina-bearing minerals and even clay. The large piles of blast-furnace and open-hearth slag in the Midwest are potential sources of manganese and phosphate. Longer-range possibilities include simultaneous extraction—perhaps at very high temperature—of several materials from “ores” like granite, which contains all the elements necessary to a modern industrial society. For higher-value materials, study seems warranted on electrostatic, electrophoretic, and other novel methods of separation. Renewable Resources Considerable scope exists for expanding the range of materials obtained from renewable resources. Wood and vegetable fibers might become important sources of primary organic chemicals, although they are not economically competitive today. Means of “cracking” the lignin molecule, the binding material in trees, could make organic chemicals available from about 25 million tons of lignin disposed of annually in this country in wood wastes with only minor recovery of values. The utility of renewable resources in general might be extended by a variety of methods: better chemical means of recovering basic materials; control of physical properties by chemical or radiation treatment; genetic modification during growth; new ways to make composite materials of natural products; and improved methods of protecting and preserving structural materials made of natural products. Resource Substitution The substitution of plentiful for less-plentiful resources is likely to become an especially important task for MSE in the future. A material may be substituted for another of the same class, as when aluminum replaces copper in electrical conductors, or for one of a different class, as when polyethylene replaces galvanized steel in buckets. We will need substitutes for certain metals that have unique and important properties but threaten to become critically scarce in the not-so-distant future. These include gold, mercury, and palladium. The nation’s balance of trade would benefit from substituting manganese for nickel as a stabilizer in stainless steels and substituting domestic ilmenite for imported rutile as a source of titanium.
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Materials and Man’s Needs Materials Science and Engineering: Volume II The Needs, Priorities, and Opportunities for Materials Research Even metals and alloys used widely in structural applications may offer broad scope for substitution by other alloys or ceramics based on substances more abundant in nature. The most common substance in the earth’s crust is silicon dioxide. It is a basic constituent of glasses, which are remarkably versatile materials used hardly at all in proportion to their potential abundance. The properties of glass include excellent corrosion resistance and very high intrinsic strength. Aluminum and magnesium—though the energy cost of obtaining them is relatively high—are abundant and display useful properties. These include, especially, the high ratios of strength-to-weight so important in engineering applications. Processing, Manufacturing Widespread opportunity exists for new processing and manufacturing techniques that waste less material and use less energy than do current methods. More processes are needed that lead directly from liquids and powders to finished shapes, thereby avoiding, for metals, the ingot and hot-working states. Such processes tend to cost less and consume less energy than do the cold-forming and machining required to shape bulk solids. Industry already shapes liquid or powders in many cases: manufacture of float glass, slip casting or compacting of intricate shapes, die casting and plastic molding, and hot forging of sintered metals. Continuous on-line assembly with minimum human intervention, a continuing objective for production lines, is virtually achieved in the manufacture of integrated circuits, where relatively few of the 200 or more processing steps are controlled actively by operators. The approach should be extended to other areas of processing and manufacturing. Some of the greatest savings in production costs and resources probably will result in the long run from greater use of small on-line computers and robots. This form of the robotics mentioned earlier for mining calls for the imaginative exploitation of a variety of sensing and monitoring devices coupled through minicomputers to control mechanisms. Environmental Effects The need to preserve the environment requires continuing development of industrial processes that release fewer harmful effluents or effluents which can be captured and converted to harmless and preferably useful forms. Some such processes are used widely now. One is the recovery of sulfur from petroleum refinery off-gases. Another is the recycling of the hydrochloric acid that has been displacing the nonrecyclable sulfuric acid in the pickling of steel for cold forming. The heavy, hard-rubber cases of automobile storage batteries are not reused and often are disposed of by burning; a lighter-weight, reusable plastic case would seem feasible. The metallic salts in polyvinyl chloride film may become an air-pollution hazard when the discarded film is burned, as in an incinerator; alternatives to the salts should be considered. To improve health and safety inside the plant, it is likely that one of the most effective moves will be wider use of robotics where working conditions are not suitable for humans.
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Materials and Man’s Needs Materials Science and Engineering: Volume II The Needs, Priorities, and Opportunities for Materials Research Improved Performance The purpose of MSE historically has been to improve performance by modifying existing materials and developing new ones. This activity will remain important. Demand will continue for higher-performance alloys, tougher glass and ceramics, stronger and tougher composites, greater magnetic strengths. But the task grows more complex as performance criteria come to embrace chemical and biological as well as mechanical and physical properties. Consumers and legislation, furthermore, are calling increasingly for materials and products that are more durable, more reliable, safer, and less toxic. To meet these requirements, a number of complex, materials-related phenomena must be elucidated. They include corrosion, flammability, thermal and photodegradation, creep and fatigue, electromigration and electrochemical action, and biological behavior. Functional Substitution Functional substitution offers great opportunity in MSE. The aim is not simply to replace one material with a better one, but to find a whole new way to do a given job. To join two metals, for example, one can develop not just stronger nuts and bolts, but adhesives. Jet engines replace piston engines and propellers in aircraft; telephones replace the mails for transmitting information. Functional substitution can lead to the revision of consumption patterns for materials and energy and, indeed, can inspire the creation of entirely new industries. Widespread use of nuclear or solar energy could yield enormous savings in the transportation of fossil fuels. The transistor started the solid-state electronics industry, which has led to technologies like computers, missile-control systems, and a broad range of industrial, medical, and leisure products. Challenging problems for functional substitution include: developing materials and techniques for new methods of generating and storing electrical energy; and finding functional substitutes and biological materials to replace human organs. Product Design The better we understand the properties of materials and how to control them, the more efficiently we can design them into products, provided that materials and design specialists work closely together from the beginning of the design and development process. The resulting interplay may change apparent design restrictions radically and achieve more effective solutions to the design problem. Purposeful blending of materials and design expertise, moreover, can contribute significantly to conservation of materials. Appropriate knowledge sometimes allows safety margins to be narrowed without hazard, thus reducing the weight of material needed in the product. Where properties like strength and elastic modulus can be upgraded, the product can sometimes be made to contain significantly less material without corresponding loss in performance. An example is the use of textured steel
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Materials and Man’s Needs Materials Science and Engineering: Volume II The Needs, Priorities, and Opportunities for Materials Research sheet in automobile bodies. Design can also be improved as a result of clarifying the functional requirements of specific parts of a product. For example, if only a surface must resist corrosion, coating or cladding may require less material and cost less than use of corrosion-resistant material throughout. Recovery, Recycling Facilitating the recovery and recycling of materials—apart from new approaches to questions like collection and separation—presents broad new problems in product design and materials selection. Product designs should ease dismantling and separation of components, but the rising costs of repair services tend to favor materials and products designed for replacement as whole units rather than for dismantling and repair. These conflicting pressures will have to be reconciled. Metals like those in a shredded automobile tend to be degraded with each recycle, although they may be quite suitable for applications less demanding than the original ones. The same is true of blended plastics, ceramics, composites, and glass. It is not clear that these problems can be solved without sacrificing performance. We must learn not only to recycle materials more efficiently; we must develop secondary and tertiary outlets for recycled materials whose properties no longer meet the requirements of the primary functions. Extractive chemistry and metallurgy will be important in improving recycling processes, but better physical methods of separation are needed, too. PRIORITIES IN GOAL-ORIENTED MATERIALS RESEARCH A study of priorities in materials research, described in detail in Chapter 5, revealed many topics having high priority for important advances in the areas of impact covered in this chapter. In particular, these priorities, which are given in Table 4.30, were obtained from analysis of several thousand write-in comments from materials professionals.
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Materials and Man’s Needs Materials Science and Engineering: Volume II The Needs, Priorities, and Opportunities for Materials Research Table 4.30 Goal-Oriented Materials Research Bearing on Areas of National Impact (Where applications are listed, the meaning, generally, is that new materials and processes are needed to advance the application.) Communications, Computers, and Control Memories; visual displays, semiconductors, thin films; integrated circuit processes, yields in large scale integration, component reliability; optical communication systems; defect properties of crystals; chemical and surface properties of electronic materials; purification; crystal growth and epitaxy; joining techniques; contacts; high temperature semiconductors. Consumer Goods Durability; visual displays; corrosion; mechanical properties; improved strength-to-weight packaging; recyclable containers; high-strength glass; plastics; plastic processing; composites. Defense and Space Mechanical properties; lasers and optical devices; energy sources; heat resistance; corrosion; radiation-damage-resistant electronics; composites; turbine blades; heat shields; thermal-control coatings; nondestructive testing; higher joining strength-to-weight-ratio materials; reliability; materials for deep-sea vehicles. Energy Battery electrodes; solid state electrolytes; seals; superconductors; electrical insulators; mechanical properties; radiation damage; high-temperature materials; corrosion; joining; nondestructive testing. Environmental Quality Less-polluting materials processes; pollution standards; recyclability; reduced safety and health hazards; extraction processes; catalysts; secondary uses for discarded materials; sorting processes; nondestructive testing; noise reduction. Health Services Implant materials; membranes; biocompatibility; medical sensors; material degradation.
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Materials and Man’s Needs Materials Science and Engineering: Volume II The Needs, Priorities, and Opportunities for Materials Research Housing and Other Construction Prefabrication techniques; corrosion; cement and concrete; weatherability; flammability. Production Equipment Friction and wear; corrosion; sensors; automation. Transportation Equipment Corrosion; pollution control; high strength-to-weight ratios; high-strength, high temperature materials; impact resistance; catalysts; adhesives; superconductors; lubricants.
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Representative terms from entire chapter: