After careful study of this chapter you should be able to do the following:
1. List six different property classifications of mate-
rials that determine their applicability.
2. Cite the four components that are involved in the
design, production, and utilization of materials,
and briefly describe the interrelationships be-
tween these components.
3. Cite three criteria that are important in the mate-
rials selection process.
Materials are probably more deep-seated in our culture than most of us realize.
Transportation, housing, clothing, communication, recreation, and food produc-
tion—virtually every segment of our everyday lives is influenced to one degree or
another by materials. Historically, the development and advancement of societies
have been intimately tied to the members’ ability to produce and manipulate materi-
als to fill their needs. In fact, early civilizations have been designated by the level
of their materials development (i.e., Stone Age, Bronze Age).
The earliest humans had access to only a very limited number of materials,
those that occur naturally: stone, wood, clay, skins, and so on. With time they
discovered techniques for producing materials that had properties superior to those
of the natural ones; these new materials included pottery and various metals. Fur-
thermore, it was discovered that the properties of a material could be altered by
heat treatments and by the addition of other substances. At this point, materials
utilization was totally a selection process, that is, deciding from a given, rather
limited set of materials the one that was best suited for an application by virtue of
its characteristics. It was not until relatively recent times that scientists came to
understand the relationships between the structural elements of materials and their
properties. This knowledge, acquired in the past 60 years or so, has empowered
them to fashion, to a large degree, the characteristics of materials. Thus, tens of
thousands of different materials have evolved with rather specialized characteristics
that meet the needs of our modern and complex society; these include metals,
plastics, glasses, and fibers.
The development of many technologies that make our existence so comfortable
has been intimately associated with the accessibility of suitable materials. An ad-
vancement in the understanding of a material type is often the forerunner to the
stepwise progression of a technology. For example, automobiles would not have
been possible without the availability of inexpensive steel or some other comparable
substitute. In our contemporary era, sophisticated electronic devices rely on compo-