Abstract: The mutually sliding members of a joint implant are each coated with a hard material selected from the group consisting of titanium carbide, oxicarbide, nitride, oxinitride, carbonitride and oxicarbonitride in order to improve the sliding, wear resistance and adhesion properties of the members.A hip joint prosthesis is provided having a socket bowl coated with titanium (oxi)nitride or titanium (oxi)carbonitride with a thickness of from 2 to 3 microns and an articular head coated with titanium (oxi)carbide or titanium (oxi)carbonitride with a thickness of from 2 to 3 microns.

Abstract: A piezoelectric detector for determination of the mass or film thickness of gaseous, liquid or solid substances being adsorbed or condensed on the surface of a piezoelectric resonator, having at least one measuring resonator with at least one integrated thin-film sensor, one discrete or integrated on the resonator re-evaporation heating element, and a reference resonator separated from the measuring resonator with a contamination shield, and protected from contamination, but not from heat radiation, with an optical window, which all allow correction by electronic or numerical means of influences of temperature changes on the resonant frequency and of cut-angle deviations and the temperature differences between the resonators.

Abstract: Machine parts are disclosed which are subjected to rolling or sliding conditions, wherein the friction partners are protected by layers with low static and dynamic coefficients of friction which are selected with regard to their tribological properties and whereby the layers are constituted by carbides and/or nitrides and/or carbonitrides and/or borides and/or silicides and/or oxides of an element or elements selected from Groups III to VIII of the Periodic Table in the form of mixtures or mixed crystals which are deposited in a suitable manner and, according to their physiochemical properties, are combined for the particular application. Preferably one of the friction partners comprises TiC or MoSi.sub.2 and the other comproses TiN or SiC or Si.sub.3 N.sub.4.

Abstract: A diffusion barrier and separation substance for metal parts which adjoin each other in an oxygen-free, inert and preferably a helium-containing atmosphere such as used in a closed-cycle high temperature reactor or gas turbine comprises first and second adjoining metal parts with a hexagonal boron nitride placed between said parts. The hexagonal boron nitride is applied to the boundary surface of the metal parts in an aqueous or organic suspension prepared as a pasty, putty-like or brushable liquid substance. The substance contains from 5 to 50% of boron nitride, from 0.5 to 30% of binders and from 2 to 6% of swelling agents and 50 to 90% liquid suspension medium. The suspension medium may advantageously contain an anti corrosive agent and in addition the formed protective film is burned from 0.25 to 3 hours at a temperature of from 100.degree. to 500.degree. C.