What are the common basic deformations of metallic materials, and what is the elastic modulus of zirconia ceramics?

Although zirconia ceramic is a material characterized by high melting and boiling points, high hardness, and resistance to separation, it can undergo 

deformation under the influence of external forces; however, this deformation is reversible, meaning the material returns to its original shape 

once the external force is removed.

In contrast to metallic materials—which typically undergo both elastic and plastic deformation stages before fracturing under static tensile 

loads at room temperature—zirconia ceramics behave differently. They generally do not exhibit a plastic deformation stage; instead, brittle 

fracture occurs immediately following elastic deformation, with minimal strain. Elongation and reduction of area are virtually zero.

In the case of metallic materials, even brittle cast iron exhibits good tensile strength; however, zirconia ceramics behave differently, displaying 

a compressive elastic modulus that is significantly higher than the tensile elastic modulus, alongside a small amount of plastic deformation under compression.

Tests indicate that the elastic modulus of zirconia ceramics is far greater than that of metals. This modulus depends not only on the nature 

of the atomic bonds but also on the types, proportions, and distribution of constituent phases, as well as porosity, since the forming and sintering 

processes significantly influence the elastic modulus.

As a brittle material, zirconia ceramics possess a compressive strength that far exceeds their tensile strength. Compared to metallic materials, 

they exhibit excellent high-temperature creep resistance and plasticity, making them suitable for applications in high-temperature environments.