Abstract: The present invention provides a method for coating a titanium based component with diamond-like carbon to reduce the thrombogeneticity of the component. In a preferred embodiment, the titanium based component is a heart valve.According to the present invention, the component is placed in a vacuum chamber and heated to about 600.degree. -650.degree. C. (1112.degree.-1202.degree. F.). Thereafter, silicon is then deposited onto the component, and the component is simultaneously bombarded with a beam of energetic ions to form a metal-silicide bonding layer. The component then is cooled to at least about 100.degree. C. (212.degree. F.), preferably about 80.degree. C. (176.degree. F.), and a diamond-like carbon precursor is condensed onto the metal-silicide bonding layer. The precursor is simultaneously bombarded with a beam of energetic ions to form a coating of diamond-like carbon.

Abstract: The present invention provides methods for modifying surfaces made from metal alloy and/or UHMWPE, preferably surfaces which are frictionally engaged, e.g., in an orthopaedic implant. The methods of the present invention reduce the coefficient of friction of the metal alloy component, reduce the shearing of fibrils from the UHMWPE component, and reduce sub-surface fatigue in the UHMWPE component. The method involves solvent immersion of the UHMWPE component to remove short chains of polyethylene at or near the surface of the component, and to swell and toughen the subsurface of the component. The method also involves firmly coating the surface of the metal alloy component with an adherent layer of diamond-like carbon ("DLC") by creating a metal-silicide interface at the surface of the metal alloy to permit firmer adhesion of DLC.

Abstract: The present invention provides a method for improving the structural integrity of polymers using a combination of high energy radiation and improved crosslinking agents. The crosslinking agents are 1,3-butadiene, three carbon cyclic compounds, three membered heterocyclic organic compounds, or linear analogues of three carbon cyclic compounds and three membered heterocyclic organic compounds, which are compact enough to diffuse to a suitable depth within the polymeric network. Preferred cyclic crosslinking agents are cyclopropane and ethylene oxide. Preferred linear crosslinking agents include propylene, 1,3-butadiene, dimethyl ether, and propane. A preferred form of high energy radiation is a beam of energetic low mass ions.

Abstract: The present invention provides a new class of precursors for forming an improved diamond-like carbon coating on a workpiece. The precursors of the present invention are paraxylylenes, preferably dimers of paraxylylene, which are solid at room temperature and which will vaporize, pyrolize to substantially monomeric form, condense onto a workpiece, and spontaneously polymerize to form a "parylene" film which is free of precursor droplets and absorbed water. Upon bombardment with an ion beam, the parylene film is converted into a uniform, pinhole-free DLC coating.

Abstract: The present invention relates to a low temperature method for making a photovoltaic material. In particular, the present invention describes a low temperature method for the deposition in vacuo of successive layers of materials required for a photovoltaic device. The present invention uses ion beam assisted processes in which a selected silicon containing precursor film is controllably converted to an amorphous silicon and carbon mixture. Ion beams are used to control the hydrogen content and thereby control the electrical conductivity of the material. The present invention further comprises the addition of a dopant and the deposition of the electrical contacts, both by thermal evaporation.

Abstract: The present invention provides for faster and stronger tissue-implant bonding by treating a ceramic implant with an ion beam to modify the surface of the ceramic. The surface modification can give the ceramic improved ion-exchange properties depending upon the particular ceramic and the type of ions used. In a preferred embodiment, a bioactive ceramic orthopaedic, dental, or soft tissue implant is bombarded with a beam of cations. When implanted in the body, the surface modification causes an increase in the release of critical ions, such as calcium or phosphorus, from the surface of the ceramic implant, and thereby accelerates implant-tissue bond formation.

Abstract: The present invention relates to an ion beam assisted method of producing a diamond like carbon (DLC) coating on the surface of a material. More particular, the invention relates to an ion beam assisted method using a fullerene precursor to produce a DLC coating, wherein the chemical composition of the ion beam and precursor are selectively chosen to determine the physical properties of the DLC coating.

Abstract: Process for forming diamond-like carbon coatings on metal surfaces to produce increased resistance to penetration, abrasion, and corrosion. A Ni/P coating is formed on an uncoated metal workpiece by-electroless deposition. While the workpiece is heated to harden the Ni/P coating, a vaporized stream of silicon is directed onto the Ni/P coating and the stream of silicon over the Ni/P coating is bombarded with an ion beam such that a NiSi.sub.2 layer is formed at the interface of the Ni/P coating and silicon and a silicon overlayer is formed over the NiSi.sub.2 layer. A vaporized stream of carbon-containing precursor molecules is directed onto the silicon overlayer such that a film of the precursor molecules condenses on the silicon overlayer. The film of precursor molecules is bombarded with an ion beam sufficiently to form a layer of diamond-like carbon on the silicon overlayer. A Ni/B solution or Ni/SiC solution can be used instead of the Ni/P solution, and germanium can be used instead of silicon.

Abstract: A work piece 13 is implanted with N.sup.+ ions from a source 1 to improve its surface hardness. The dosage of implanted ions is monitored by a member 14 which changes its color in dependence upon the dose. The member 14 may comprise a tantalum plate 15 with an anodic oxide layer 16 of a thickness to produce interference colors. In accordance with the invention this layer 16 changes colors as a function of the ion dosage.

Abstract: An apparatus 10 and a method are provided for treating silicon wafers 26 in vacuum with an ion beam B and for controlling the temperature of the wafers 26. The wafers 26 are mounted on a drum 22 which is rotated through the ion beam B, and which is large enough that the mean equilibrium temperature of the wafers 26, in the absence of any other energy sources, would be less than the desired temperature. The wafers 26 are additionally heated by infra-red lamps 34 so the desired temperature is achieved.

Abstract: A process for hardening the surface of a metal body in which the surface is first bombarded with ions capable of occupying interstitial sites in its crystal lattice, then a coating of a reactive metal is deposited on the surface, and finally the coating is bombarded with ions which will react with it to form a hard material such as a carbide or nitride. The bombardment is continued until the hard material has become embodied in the surface by means of radiation enhanced diffusion.

Abstract: Bodies made of titanium or its alloys, having surfaces liable to wear, have their wear resistance improved by coating such surfaces with a layer of a metal such as tin or aluminum which has been bombarded with ions of a light species such as nitrogen, carbon, boron, or neon so as to cause the metal to migrate into the titanium or titanium alloy. The modified surface has improved wear resistance and reduced coefficient of friction.

Abstract: A process for producing regions of high resistivity in gallium arsenide, and other related compounds and mixed crystals which show electrical behavior which is similar to that of gallium arsenide, in which deuterons are implanted into a substrate made of the semi-conductor body with energies up to a maximum value corresponding to a desired depth of penetration into the body. Apparatus for carrying out the process also is described.

Abstract: A process for improving the wear resistance of, and reducing the frictional forces between, bodies made of titanium or its alloys, in which surfaces liable to wear are coated with a layer of a metal such as tin of aluminium which is then bombarded with ions of a light species such as nitrogen, carbon, boron, or neon so as to cause the metal to migrate into the titanium.

Abstract: A process for manufacturing gallium arsenide devices in which regions of high resistivity are created in the gallium arsenide by subjecting the regions to bombardment by protons and then by deuterons, and devices so made.

Abstract: A process for treating a titanium containing artefact to inhibit fretting corrosion, in which an active species having a higher heat of formation of its oxide than titanium is deposited on the artefact in vacuo, and the artefact is then heated sufficiently to cause the active species to migrate into the artefact to provide a surface region thereof containing the active species. Preferably the active species is deposited by an ion bombardment technique.

Abstract: A method is provided for treating a metal working tool element made of cemented carbide materials, as hereinafter described, comprising the operation of implanting into a working surface of the tool element ions of a material such as to modify the implanted region of the working surface of the tool element in such a way as to prevent adhesion between the matrix metal of the cemented carbide tool element and a metal being worked by the tool element. Metal working tool elements so treated are also disclosed.