Stress-strain behavior of high porous zirconia ceramic

In this work, we studied the deformation behavior of ZrO 2 ceramics stabilized with 5.5 wt.% Y 2 O 3 with a porosity of 4 -42% during diametral compression tests ("Brazilian" test).It has been shown that with an increase in porosity from 4 to 42%, the ultimate tensile strength in diametral compression decreases from 115 to 9 MPa.The ultimate strain before fracture decreases from 1 to 0.8%.The effective modulus also decreases with increasing of porosity.The analysis of the "stress-strain" curves showed that the deformation behavior of ceramics is influenced by both the volume and the morphology of the pore space.It been shown that two strain exponent were observed, which indicate a change of deformation mechanism of the ceramic during loading.X-ray diffraction analysis carried out from the front surface of fracture fragments of samples with porosities of 4, 17, and 42% showed that in these materials microstructural parameters such us the size of the coherently diffracting domains of the tetragonal phase and lattice microdistortion changes in comparison with the initial state after sintering.These materials microstructural parameters are changes non-uniformly, which indicate the inhomogeneity of the deformation of this brittle material during compression.