Abstract: A roller body or plain bearing component exhibits a core body (1) of ceramic material which is coated with a lapped hard layer (3) (e.g. titanium carbide, Diamond . . . ).

Abstract: A contact sensing probe with a cylindrical housing component (1), with a bearing (4) and a hemispherical element (3), possesses a stylus (13) which displaces the hemispherical element (3) and, with that, the transmission element (2). A measured value converter (14) is provided within the contact sensing probe. The running surfaces (1a, 2a) of the housing component (1) and the transmission element (2) comprise high strength ceramic material with a mean roughness value R.sub.a of .ltoreq.0.8 .mu.m, respectively 32 .mu.in. Rotational security is provided not only for the hemispherical element (3) but also for the transmission element (2).

Abstract: Process for applying a catalyst layer (4) composed of noble metals and/or noble-metal compounds to a ceramic carrier (1), in which process at least one ceramic intermediate layer (2) based on a glaze is applied, subjected to a heat treatment and cooled down. The catalyst layer (4) is in turn deposited as a chemical, electrochemical or physical deposit. Variants with .gamma.-Al.sub.2 O.sub.3 intermediate layer or with SiO.sub.2 intermediate layer or with Si intermediate layer.

Abstract: Process for applying a catalyst layer (4) composed of noble metals and/or noble-metal compounds to a ceramic support (1), in which a foil (2) made of an Ag/Ti alloy is first placed on the surface of the support (1) and this is fused in vacuo by heat treatment, cooled down again and firmly bound to the support (1). The catalyst layer (4) is in turn deposited in an electrochemical manner on the electrically conducting intermediate layer.