Ductile ceramics

This chapter considers the mechanical properties of ductile ceramics, which can be grouped into three categories as classified below  

Pelleg, Mechanical Properties of Ceramics, Solid Mechanics and Its Applications 213, DOI 10.1007/978-3-319-04492-7 2, Springer International Publishing Switz land 2014 

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Polymers have a low stiffness, and (in the right range of temperature) are ductile. Ceramics and glasses are stiff and strong, but are catastrophically brittle. In fibrous... 

Waku Y, Nakagawa N, Wakamoto T, Ohtsubo H, Shimizu K, Kohtoku Y (1997) A ductile ceramic eutectic composite with high strength at 1873 K. Nature 389 49-52... 

The unconfined compressive strength used in the above equation is 3,872 126 MPa, as seen in Fig. 1.46. A discussion about the effects of temperature and strain rates on the compression stress-strain curves is found in later sections dealing with ductile ceramics and the infiuence of impact on the strength properties of ceramics. 

One of the important features of impact testing is the evaluation of the ductile-to-brittle transition temperature. What, then, is the purpose of discussing the impact testing of ceramics, since most are brittle at ambient temperature (and clearly at low temperatures) Yet, impact tests are also performed on classic, brittle materials in order to evaluate the energy absorbed during the fracturing process. Furthermore, some brittle ceramics are ductile at sufficiently elevated temperatures, so the brittle-ductile transition may still be of interest. Ductile and superplastic ceramics will be discussed in depth in Chap. 2 (on ductile ceramics), while the present section deals with the actual process of performing impact tests. 

This section deals with the features of ductile ceramics and, in some cases, the modifications in composition that induce ductility at low temperatures, as well as additives to base ceramics, such as metals, which also promote ductility. 

Kim et al. [28], in their extensive work on superplasticity, classified materials on the basis of their elongations, defining superplasticity as being ductility beyond 200 %. In accordance with their classification system superplastic-like materials are those with elongations in the 50-200 % range ductile ceramics have... 

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