ABSTRACT

This chapter describes the porosity and some micro-crack dependence of other ceramics and materials. It demonstrates the broad similarities and some differences of primarily the porosity and secondarily the microcrack dependences of the properties of monolithic ceramics relative to those of plastics, metals, plasters, cements, and traditional and designed ceramic composites. The chapter show that the location of pores in one or the other of, or between, the phases of a composite can be important in the porosity effects on properties. It also shows that much more study and characterization of microcracks is needed, especially to differentiate between those that are preexisting versus those generated with macrocrack propagation and their increases in fracture toughness, and tough-nesses and Weibull moduli are often, and strengths are usually if not always, less in microcracked than nonmicrocracked bodies.