A Historical Perspective on the Toughness of Ceramics

In this paper, we discuss fracture problems experienced by engineers early in the twentieth century, before fracture mechanics was developed and before we had a systematic way to characterize the fracture resistance of ceramic materials. Universal mechanical test machines and standard methods of establishing material performance under mechanical loads did not exist. Yet the needs for mechanical reliability were there, just as they are today. We review some of the problems encountered by engineers in designing with ceramic materials at the beginning of the twentieth century that are still problems today, but on materials with very different use. We shall show how the development of fracture mechanics and modern techniques of microstructural analysis enabled the solution of mechanical problems associated with the ceramics in modern applications. In the course of the paper we will trace the development of fracture mechanics from the early twentieth century to the present day and the replacement of performance tests with design criteria based on fracture mechanics analysis.