Disclosed is a method of forming dense protective coatings of co-deposited aluminum oxide and titanium oxide on wear surfaces. The coating is formed by simultaneously reacting an aluminum halide gas and a titanium halide gas with water vapor on a surface maintained at a temperature of about 900.degree. C to about 1250.degree. C. Reaction conditions are maintained to assure mixing of the titanium halide gas with the other reactants only in the reaction zone and compositions of the reactant gases are limited to produce a coating comprising alpha alumina (Al.sub.2 O.sub.3) with about 2% to about 10% hexagonal alpha titanium oxide (Ti.sub.2 O.sub.3) dispersed in the alumina matrix.

A method is disclosed for preventing stress corrosion cracking or metal embrittlement of a zirconium or zirconium alloy container that is to be coated on the inside surface with a layer of a metal such as copper, a copper alloy, nickel, or iron and used for holding nuclear fuel material as a nuclear fuel element. The zirconium material is etched in an etchant solution, desmutted mechanically or ultrasonically, oxidized to form an oxide coating on the zirconium, cleaned in an aqueous alkaline cleaning solution, activated for electroless deposition of a metal layer and contacted with an electroless metal plating solution. This method provides a boundary layer of zirconium oxide between the zirconium container and the metal layer.

Disclosed is a method of forming dense protective coatings of co-deposited aluminum oxide and titanium oxide on wear surfaces. The coating is formed by simultaneously reacting an aluminum halide gas and a titanium halide gas with water vapor on a surface maintained at a temperature of about 900.degree. to about 1250.degree. C. Reaction conditions are maintained to assure mixing of the titanium halide gas with the other reactants only in the reaction zone and compositions of the reactant gases are limited to produce a coating comprising alpha alumina (Al.sub.2 O.sub.3) with about 2% to about 10% hexagonal alpha titanium oxide (Ti.sub.2 O.sub.3) dispersed in the alumina matrix.

A method for coating a substrate with a radioisotope comprising is disclosed. The method comprises immersing the substrate within a solution containing a .gamma., .beta..sup.+, .alpha. or .beta..sup.- emitting radioisotope, then exposing the immersed substrate to tuned vibrational cavitation (i.e. ultrasonic) to produce a coated substrate, followed by baking the coated substrate at a temperature below the recrystallization temperature of the substrate. Following this step, the substrate is rinsed and dried. Substrates coated using the method of this invention exhibit very low rates of leaching of the coated radioisotope, and are suitable for use within medical applications.

This invention relates to radioactively coated devices, preferably radioctively coated medical devices. These coated devices are characterized as having a low rate of leaching of the radioisotope from the surface of the coated device and a uniform radioactive coating, and are therefore suitable for use within biological systems. Methods for coating a device with a radioisotope comprising are also disclosed. One method comprises immersing the device within a solution containing a .gamma., .beta..sup.+, .alpha., .beta..sup.- or .epsilon. (electron capture) emitting radioisotope, then exposing the immersed substrate to tuned vibrational cavitation to produce a coated substrate. A second method involves coating a substrate using electroless plating, and yet a third method involves the use of electroplating a radioisotope onto a substate of interest. With these methods, the coating procedures are followed by baking the coated substrate at a temperature below the recrystallization temperature of the substrate. Substrates coated using the methods of this invention exhibit very low rates of leaching of the coated radioisotope, and are suitable for use within medical applications, for example as stents, catheters, seeds, protheses, vavles, staples and other wound closure devices, where a localized therapeutic treatment is desired.