By Carl Zweben
Zweben Consulting, Devon, Penn.
The development of composite materials as well as the related design and manufacturing technologies is one of the most important advances in the history of materials. Composites are multi-functional materials having unprecedented mechanical and physical properties which can be tailored to meet the requirements of a particular application. Many composites also exhibit great resistance to wear, corrosion, and high-temperature exposure.
These unique characteristics provide the mechanical engineer with design opportunities not possible with conventional monolithic (unreinforced) materials. Composites technology also makes possible the use of an entire class of solid materials, ceramics, in applications for which monolithic versions are unsuited because of their great strength scatter and poor resistance to mechanical and thermal shock. Further, many manufacturing processes for composites are well adapted to the fabrication of large, complex structures, which allows consolidation of parts, reducing manufacturing costs.
Composites are important materials which are now used widely in a large and increasing number of commercial mechanical engineering applications, such as the aerospace industry; internal combustion engines; machine components; thermal management and electronic packaging; automobile, train, and aircraft structures and mechanical components, such as brakes, drive shafts, flywheels, tanks, and pressure vessels; dimensionally stable components; process industries equipment requiring resistance to high-temperature corrosion, oxidation, and wear; offshore and onshore oil exploration and production; marine structures; sports and leisure equipment; ships and boats; and biomedical devices.
Biological structural materials occurring in nature are typically some type of composite. Common examples are wood, bamboo, bone, teeth and shell. Further, use of artificial composite materials is not new—straw-reinforced mud bricks were employed in biblical times. In modern terminology, this material would be classified as an “organic, fiber-reinforced ceramic matrix composite.”
Reprinted from Mechanical Engineers’ Handbook, Fourth Edition, edited by Myer Kutz, ©2015 John Wiley & Sons, Inc.