Abstract: Prostheses with artificial joints have only a few metallic and ceramic materials whose compatibility with human or animal tissue has been established. These materials, however, cannot be combined with one another in any manner if a friction pairing occurs as a result, for example, in the case of artificial joints. With artificial joints, joint partners are required to have good mechanical properties as well as tribological properties. According to the invention, a sintered material is thus provided which is comprised of zircon oxide with an addition of 0.1 to 40 wt. % aluminum oxide. This sintered material enables an artificial joint of a prosthesis whose other ceramic materials are comprised of aluminum oxide or zircon oxide with the given proportions of aluminum oxide to be assembled with joint partners.

Abstract: A ceramic socket or ceramic socket insert for a hip joint prosthesis is tested prior to implantation in a human body by subjecting the portions of the interior of the socket or socket insert to a load that generates stresses that are greater than the physiological load. This may be accomplished either by pressing a hemispherically-shaped deformable material such as polymer or plastic into the interior of the socket or socket insert or by exposing the interior of the socket or socket insert to a fluid under pressure. The interior of the socket or socket insert may be sealed off with a test punch that has a supply line for the fluid. To reduce the amount of fluid that is required, the test punch may have a bulge that projects into the interior of the socket or socket insert and leaves only a gap for the fluid.

Abstract: The invention relates to a ceramic molding which is manufactured from high-temperature resistant, fire-resistant or refractory fibers and fine-grain, fire-resistant or refractory materials and, in certain cases, from other customary additives. The ceramic molding is characterized by the fact that its porosity gradually and continuously increases along an axis of the molding from less than 20% to more than 70%. The areas with low porosity comprise the fine-grain, fire-resistant or refractory materials. The areas of high porosity comprise ceramic fiber, such as, fibers of Al.sub.2 O.sub.3, SiO.sub.2, ZrO.sub.2, C, SiC or mixtures thereof. The intermediate areas are constructed of mixtures of ceramic fiber and fire-resistant or refractory materials. The invention also relates to the use of such a ceramic molding method for the manufacture of compound moldings saturated or infiltrated with organic resins, pitch, tar, metals, metal alloys or glasses.