Metallurgy and the Evolution of Materials Science and Engineering
Abstract of the lecture
Materials have become Increasingly ingrained in human existence ever since the emergence of mankind some hundred thousand years ago. The association between civilization and materials has intensified to the extent that, presently, about 15 billion tons of raw materials are taken annually from nature by mining, drilling, harvesting and fishing for conversion into countless edifices, machines, devices, and products for societal purpose. Nevertheless, despite the magnitude and importance of this world-wide enterprise, often referred to as the global materials cycle, it has been only within the past thirty years that the field of materials has come into intellectual focus. This has been accomplished, in effect, by carrying over the central theme of metallurgy (namely, the interrelationships between the processing, structure, properties, and performance of the metallic state) to other classes of materials that are potentially accessible and useful to society. In other words, the discipline of metallurgy has provided an excellent paradigm for the newer and broader field of materials science and engineering (MSE), within which metallurgy has now become an indispensable part. However, the several disciplines which function within MSE have not yet blended sufficiently to operate as a unified branch of knowledge, and so MSE must still be viewed as a multidiscipline in a vibrant state of change. It will take time, perhaps another generation of two, for society to determine whether MSE can actually evolve into a coherent discipline unto itself in competition with other branches of knowledge which are striving for attention. The crucial test is likely to depend on two subtle criteria: How well will MSE aid the human mind to understand nature ever more thoroughly, and how well will MSE help society to utilize nature ever more wisely?
Conceptually, metallurgy and MSE have much in common. In both cases, there is no clear separation between their scientific and engineering contents, and both gather special strength from this deliberate continuity. Both function most productively when there is an intimate mixing of scientific and experienced knowledge; yet major advances in this interplay are found to be initiated more frequently by novel processing and new experimental findings than by new theory. Hence, the hallmark of MSE thus far, as in metallurgy, is not the predictability of material behavior from first principles, but the synergistic reciprocities which are discovered between processing and structure, structure and properties, properties and performance. The operations of these interrelationships are nicely illustrated by examples of recent advanced-material developments.