Significance, History, and Sources of Materials

To most engineers and scientists a material is a solid with useful structural, electrical (including electronic or magnetic), optical or corrosion-resistance properties. If we accept this definition then it is clear that the products of most of the major manufacturing industries are either materials or are fabricated from materials. The exceptions are the food, beverage, chemical and fuels industries; even within these industries materials play a key role. Examples are the steel, aluminum and glass used for packaging food and drink, corrosion-resistant materials used to build chemical reactors, and the bits used to drill oil wells. Materials, then, have a great importance in the economies of industrialized nations. In this text we shall be concerned with materials of mineral origin, so that steel, glass, silicon, and ceramic materials are included, but materials of animal or vegetable origin (wood, rubber, leather, etc.) are excluded. As extracted from the earth, the minerals (“raw materials” in Fig. 1.1) from which these materials are produced have a value of 0.4 percent of the U.S. gross domestic product. However, processing of these minerals (coupled with recycling of old materials) to produce metals, ceramics, etc. brings their value to over 4 percent of the GDP.1