Effect of quasi-hydrostatic compression on the mechanical properties of ceramics in the ZrO2+3 mol.% Y2O3 system

The effect of quasi-hydrostatic compression on the strength of ZrO2 + 3 mol.% Y2O3 ceramic specimens of two series was studied. The series I ceramic was a powder commercially available from TOSOH Co. (Japan), with a density of 6.1g/cm(3), and the series 2 ceramic was a powder with a density of 5.9 g/cm(3) prepared under laboratory conditions at the IPM Research Institute (National Academy of Sciences, Ukraine). The pressure range was up to 1.2 GPa, and the pressure-transmitting medium was a coarse-grained corundum powder. In the series I specimens, the strength increases with pressure over the entire pressure range (from 670 MPa to 1098 MPa at 1.2 GPa); in the series 2 specimens, the strength increases only to a pressure of 0.8 GPa (from 695 MPa to 828 MPa) and then, with further increase in pressure drops sharply to nearly zero (30 MPa at 1.2 GPa). It Was proposed that the observed effect might be associated with a martensite transformation in the zone of structural imperfections (discontinuities). On reaching a critical value determined by the strength of the matrix, the martensite transformation becomes a cause of failure of the material.