evaluated the performance of materials as structural or functional elements in engineering systems.
In conducting all these studies, materials scientists and engineers have recognized that properties and performance depend on structure and composition, which in turn are the result of the synthesis or processing of a material. Only recently, however, have synthesis and processing come to be widely viewed as an essential and integral element of materials science and engineering. As discussed in Chapter 3, synthesis of new materials by unusual chemical routes and by various physical and chemical means has led to an era in which atom-by-atom fabrication can be achieved. Coincidentally, processing has received renewed attention, partly in response to challenges from international competitors who have reaped the benefits of improved quality and uniformity of traditional materials, and partly in response to the demands for process control to achieve the promise of advanced materials.
Increasingly, work in materials science and engineering involves interactions among groups working in all elements of the field. One example of this trend is the development of new high-temperature intermetallic composites to achieve a complex array of performance-driven properties for applications such as the proposed national aerospace plane. If materials science and engineering is to remain healthy and productive, research on all elements of the field—and on their relationships—is vital. Nonetheless, the committee has emphasized synthesis and processing as the aspect of the field representing the greatest national weakness and also the ripest opportunities. In addition, concluding sections of this chapter discuss instrumentation and modeling, which are the areas of research critical to synthesis and processing as well as to the other elements of the field.
More detailed discussions of these significant aspects of materials science and engineering are presented in Appendixes A, B, C, D, and E, which describe important research opportunities in synthesis, processing, performance, instrumentation, and analysis and modeling, respectively. This information should be useful to the practitioners of materials science and engineering as well as to the federal agencies seeking specific advice on technical areas of research.
Properties are the descriptors that define the functional attributes and utility of materials. The brilliance and transparency of diamond, for example, give rise to its use as gemstones as well as sophisticated optical coatings, while its great hardness and thermal conductivity permit quite different applications such as cutting tools and media. A micrograph of a diamond thin film is shown in Figure 4.1. Metals are ductile, a property that facilitates their being processed into wires for electrical conduction or for mechanical retention.