Abstract: The invention is a method of qualifying an implantable ceramic component made of high-purity dense yttria tetragonal zirconium oxide polycrystal (Y-TZP) by application of non-destructive tests. Specifically, a qualified Y-TZP ceramic component or witness sample is examined by X-ray diffraction to determine the initial monoclinic phase content. The component or witness sample is exposed to steam at 127° C. for a predetermined period of time, preferably six hours. The monoclinic phase content is determined for the post-exposure sample. The absolute difference between the initial monoclinic phase content and the post-exposure monoclinic phase content is calculated by difference. If the difference is less than 2.1% the sample is accepted. In an alternate embodiment, the components that pass the screening test are examined by ultrasonic testing to evaluate soundness of the ceramic component. Any component that presents a flaw of greater than three microns is rejected.

Abstract: The invention is a method of bonding a ceramic part to a metal part by heating a component assembly comprised of the metal part, the ceramic part, and a compatible interlayer material such as titanium-nickel alloy placed between the two parts and heated at a temperature that is greater than the eutectic temperature of the interlayer material, where alloys, intermetallics or solid solution formed between the metal part and the metal interlayer material, but that is less than the melting point of either the ceramic part or the metal part. The component assembly is held in intimate contact at temperature in a non-reactive atmosphere for a sufficient time to develop a hermetic and strong bond between the ceramic part and the metal part. The bonded component assembly is optionally treated with acid to remove unwanted materials, to assure a biocompatible component assembly for implantation in living tissue.

Abstract: The invention is a method of bonding a ceramic part to a metal part by heating a component assembly comprised of the metal part, the ceramic part, and a very thin essentially pure interlayer material of a compatible interlayer material placed between the two parts and heated at a temperature that is greater than the temperature of the eutectic formed between the metal part and the metal interlayer material, but that is less than the melting point of either the interlayer material, the ceramic part or the metal part. The component assembly is held in intimate contact at temperature in a non-reactive atmosphere for a sufficient time to develop a hermetic and strong bond between the ceramic part and the metal part. The bonded component assembly is optionally treated with acid to remove any residual free nickel and nickel salts, to assure a biocompatible component assembly for implantation in living tissue.

Abstract: The invention is a method of bonding a ceramic part to a metal part by heating a component assembly comprised of the metal part, the ceramic part, and a very thin essentially pure interlayer material of a compatible interlayer material placed between the two parts and heated at a temperature that is greater than the temperature of the eutectic formed between the metal part and the metal interlayer material, but that is less than the melting point of either the interlayer material, the ceramic part or the metal part. The component assembly is held in intimate contact at temperature in a non-reactive atmosphere for a sufficient time to develop a hermetic and strong bond between the ceramic part and the metal part. The bonded component assembly is optionally treated with acid to remove any residual free nickel and nickel salts, to assure a biocompatible component assembly for implantation in living tissue.

Abstract: A method of bonding a stainless steel part to a titanium part by heating a component assembly comprised of the titanium part, the stainless steel part, and a laminated titanium-nickel filler material placed between the two parts and heated at a temperature that is less than the melting point of either the stainless steel part or the titanium part. The component assembly is held in intimate contact at temperature in a non-reactive atmosphere for a sufficient time to develop a hermetic and strong bond between the stainless steel part and the titanium part. The bonded component assembly is optionally treated with acid to remove any residual free nickel and nickel salts, to assure a biocompatible component assembly, if implanted in living tissue.

Abstract: A method of bonding a stainless steel part to a titanium part by heating a component assembly comprised of the titanium part, the stainless steel part, and a compact titanium-nickel filler material placed between the two parts and heated at a temperature that is less than the melting point of either the stainless steel part or the titanium part. The compact filler material is made of particles, preferably spheres, of discrete layers of nickel and titanium metal that react with each other and with the stainless and titanium parts to form a strong assembly when thermally processed. The component assembly is held in intimate contact at temperature in a non-reactive atmosphere for a sufficient time to develop a hermetic and strong bond between the stainless steel part and the titanium part.

Abstract: An implantable miniature bonded device comprising a bimetallic electrode hermetically bonded to a ceramic tube that contains electrical components for processing electrical signals that are communicated to or from living tissue via an electrically conductive wire. The ceramic tube is an electrical insulator that is biocompatible and that is bonded to a titanium electrode part, which in turn is bonded to a stainless steel electrode part by brazing. Degradation of the electrical conductivity between the wire and the device is avoided by attaching an electrically conductive wire directly to the stainless steel part, rather than to the titanium part.

Abstract: The invention is a method of bonding a stainless steel part to a titanium part by heating a component assembly comprised of the titanium part, the stainless steel part, and a very thin substantially pure nickel filler material placed between the two parts and heated at a temperature that is greater than the temperature of the eutectic formed between the titanium part and the substantially pure nickel filler material, but that is less than the melting point of either the filler material, the stainless steel part, or the titanium part. The component assembly is held in intimate contact at temperature in a non-reactive atmosphere for a sufficient time to develop a hermetic and strong bond between the stainless steel part and the titanium part. The bonded component assembly is optionally treated with acid to remove any residual free nickel and nickel salts, to assure a biocompatible component assembly for implantation in living tissue.

Abstract: The invention is a method of bonding a ceramic part to a metal part by heating a component assembly comprised of the metal part, the ceramic part, and a very thin essentially pure interlayer material of a compatible interlayer material placed between the two parts and heated at a temperature that is greater than the temperature of the eutectic formed between the metal part and the metal interlayer material, but that is less than the melting point of either the interlayer material, the ceramic part or the metal part. The component assembly is held in intimate contact at temperature in a non-reactive atmosphere for a sufficient time to develop a hermetic and strong bond between the ceramic part and the metal part. The bonded component assembly is optionally treated with acid to remove any residual free nickel and nickel salts, to assure a biocompatible component assembly for implantation in living tissue.

Abstract: The invention is a method of bonding a ceramic part to a metal part by heating a component assembly comprised of the metal part, the ceramic part, and a compatible interlayer material such as titanium-nickel alloy placed between the two parts and heated at a temperature that is greater than the eutectic temperature of the interlayer material, where alloys, intermetallics or solid solution formed between the metal part and the metal interlayer material, but that is less than the melting point of either the ceramic part or the metal part. The component assembly is held in intimate contact at temperature in a non-reactive atmosphere for a sufficient time to develop a hermetic and strong bond between the ceramic part and the metal part. The bonded component assembly is optionally treated with acid to remove unwanted materials, to assure a biocompatible component assembly for implantation in living tissue.

Abstract: The invention is a method of qualifying an implantable ceramic component made of high-purity dense yttria tetragonal zirconium oxide polycrystal (Y-TZP) by application of non-destructive tests. Specifically, a qualified Y-TZP ceramic component or witness sample is examined by X-ray diffraction to determine the initial monoclinic phase content. The component or witness sample is exposed to steam at 127° C. for a predetermined period of time, preferably six hours. The monoclinic phase content is determined for the post-exposure sample. The absolute difference between the initial monoclinic phase content and the post-exposure monoclinic phase content is calculated by difference. If the difference is less than 2.1% the sample is accepted. In an alternate embodiment, the components that pass the screening test are examined by ultrasonic testing to evaluate soundness of the ceramic component. Any component that presents a flaw of greater than three microns is rejected.

Abstract: The invention is directed to an apparatus and a method of substantially eliminating destructive low-temperature, humidity-enhanced phase transformation of yttria-stabilized zirconia in general, as well as eliminating low-temperature degradation of yttria-stabilized tetragonal zirconia polycrystalline ceramic (Y-TZP). The martensitic-type phase transformation from tetragonal to monoclinic is accompanied by severe strength degradation in a moist environment at low-temperature, specifically at room temperature as well as at body temperature. This class of materials has been chosen as the packaging material for small implantable neural-muscular sensors and stimulators because of the high fracture toughness and high mechanical strength. This destructive phase transformation has been substantially eliminated, thus ensuring the safety of long-term implants, by subjecting the sintered components to post-machining hot isostatic pressing, such that the average grain size is less than about 0.5 microns.

Abstract: The invention is a method of bonding a ceramic part to a metal part by heating a component assembly comprised of the metal part, the ceramic part, and a very thin essentially pure interlayer material of a compatible interlayer material placed between the two parts and heated at a temperature that is greater than the temperature of the eutectic formed between the metal part and the metal interlayer material, but that is less than the melting point of either the interlayer material, the ceramic part or the metal part. The component assembly is held in intimate contact at temperature in a non-reactive atmosphere for a sufficient time to develop a homogeneous and strong bond between the ceramic part and the metal part. The bonded component assembly is optionally treated with acid to remove any residual free nickel and nickel salts, to assure a biocompatible component assembly for implantation in living tissue.

Abstract: The invention is a method of bonding a ceramic part to a metal part by heating a component assembly comprised of the metal part, the ceramic part, and a very thin essentially pure interlayer material of a compatible interlayer material placed between the two parts and heated at a temperature that is greater than the temperature of the eutectic formed between the metal part and the metal interlayer material, but that is less than the melting point of either the interlayer material, the ceramic part or the metal part. The component assembly is held in intimate contact at temperature in a non-reactive atmosphere for a sufficient time to develop a homogeneous and strong bond between the ceramic part and the metal part. The bonded component assembly is optionally treated with acid to remove any residual free nickel and nickel salts, to assure a biocompatible component assembly for implantation in living tissue.