A significant clinical problem in the use of joint prostheses with polyethylene and metal components is the polyethylene wearout. Modifications of surfaces of titanium alloys with bio-compatible hard material coatings like (Ti, Nb)N, (Ti, Nb)ON, (Ti, Ta)N TaON and Ta_2O_5 are tested as a wear protection for the polyethylene component. A special hard coating design can be achieved by a reactive arc physical vapor deposition technique, using partitioned targets. The coatings were physically characterized by SNMS, EDX, SEM, XRD, scratch-tests, corrosion resistance and contact angle measurements. Biological tests included investigations concerning zyto-toxic behavior, vitality of cells and the Northern-ELISA method. Especially (Ti, Nb)ON and Ta_2O_5 films qualified for the coating of joint prostheses because of their high corrosion resistance, their high adhesion to the substrates and the ability of reproducible industrial production. (orig.)SIGLEAvailable from TIB Hannover: F99B901+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Bildung, Wissenschaft, Forschung und Technologie, Bonn (Germany)DEGerman