| abstract |
A material comprising: from 98-50% by volume of zirconia as a matrix, which is stabilized with i) either of from about 2 to about 3 mole percent of yttria ii) or of from about 10 to about 15 mole percent of ceria; iii) or a mixture of ceria and yttria in the range of amounts as given in i) and ii) the stabilizing oxides may be substituted against each other in a ratio from 1:99 to 99:1 and a maximum stabilization of 3 mole percent related to pure yttria and 15 mole percent related to pure ceria respectively are not exceeded, and wherein the term mole percent is related to the zirconia matrix and wherein the zirconia matrix is obtainable from a) a powder of particles of zirconia having a mean particle size of < 0.35 µm, b) the particles are coated with the stabilizing oxides yttria and/or ceria for stabilizing zirconia, c) a stabilization of the tetragonal phase is performed via a diffusion reaction by a sintering process, and from about 2 to about 50% by volume of alumina of which from about 5 to about 90% by volume is in the form of hexagonal platelets of general formula REAl11O18 which are formed at sintering temperatures of less than 1 500 °C. |