| abstract |
An artificial joint made from a zirconia-alumina composite ceramic and having the capability of providing a good joint motion for a long time period with a high degree of reliability is provided. This artificial joint is composed of a first bone member and a second bone member, which is slidably engaged to a part of the first bone member to form a joint portion. At least one of the first and second bone members is made from the zirconia-alumina composite ceramic comprising a matrix phase of zirconia grains and a second phase of alumina grains dispersed in the matrix phase. The zirconia grains contains ceria as a stabilizer in such an amount that the matrix phase is largely composed of tetragonal zirconia. In addition, this composite ceramic has an average grain size of 0.1 to 1 μm, preferably 0.1 to 0.8 μm, and particularly preferably 0.1 to 0.65 μm. |